222 P; CAMERON. HYMENOPTERA. transverse, thè apex transverse, an irregular, longish oval spot on the apex of the mesopleurae on the upper half and having a small roundish spot on its base below, a large transverse mark, gradually narrowed inwardly, the end rounded, an oval spot, more narrowed above than below, on the middle of the metapleurae, the apices of the basal six abdominal segments, the ist line dilated laterally at the base, the 2™* with the base roundly narrowed; the other lines become gradually narrower, and the last segment entirely whitish yellow. Four front legs whitish yellow, the femora tinged with fuscous on the anterior, with rufous on the posterior; the hind coxae, apical joint of hind trochanters, the femora broadly on the sides and below, the base of the tibiae narrowly, the rest except for a white band near the base and 2 on the lower side and the basal half of the metatarsus, the rest of the tarsi white; the basal threefourths of the middle basal tarsal joint fuscous. Wings hyaline, the stigma and nervures black. cfLength 11 m.m. Smooth, an oblique striated band on the upper half of the mesopleurae; the mesopleural furrow striated, more finely at the base than on the apex; the metapleurae finely obliquely striated, the metanotum behind the keel obliquely, on the apex more closely and finely obliquely striated. Metanotal spines short, broad, the metanotum has a straight, longish oblique slope. 3. Mesostenoideus trianguliferus sp. n. Bivak Island, February. Black, the palpi, a large, longish triangular mark on the sides of the vertex, the 2 uniting in front of the ocelli and extending shortly behind them, scutellum, a conical mark, twice longer than wide, below the fore wings, one of the same length, but square, below the posterior pair, a conical mark, the narrowed end at the apex, in the middle of the metapleurae, lines dilated laterally, on the apex of the basal two abdominal segments, a narrower one of almost equal width, on the 3^, a longish line on the sides of the 4*, and the whole of the apical 2, yellowish white; the anterior legs whitish yellow, the basal two-thirds of the coxae black, the femora infuscated above and the tibiae, except at the base and apex, on the outerside, the tarsi fuscous, joints 2 and 3 white at the base; the middle coxae white, black at the base below, the middle femora dark rufous, broadly black below, the tibiae white, narrowly black at the base and apex, the tarsi black, the apex of the i*t narrowly and the 2nd and 3rd white, Wings hyaline, the stigma and nervures black, the areolet minute, open at the apex, the transverse median nervure received shortly behind the transverse basal; the disco-cubital nervure bluntly angled, not broken. Q. Length 9 mm., terebra 2 m.m. Face strongly punctured in the centre, which is bordered by a strong transversely striated band, the outer edge being smooth. Front and vertex smooth; the black ocellar region forms a triangle. Metanotum closely transversely striated, the striae more or less curved, the metapleurae closely obliquely striated, the striae stronger at the base. The base and apex of the propleurae striated, the two bands uniting in the centre; there is an oblique band of striae on the upper two-thirds of the meso-pleurae. Abdomen smooth and shining. 226 P. CAMERON. HYMENOPTERA. commencing, on the innerside, at the same place as the preceding one, but not reaching to the outer edge and the last segment entirely, pale yellow with the usual pale markings on the ventral segments. Front legs whitish yellow, their coxae black to near the apex, but with the black broadly divided in the middle on the lower, outerside, the femora fuscous above, the tarsi fuscous; the middle coxae black, with a broad oblique mark on the outer basal half, the trochanters white, the femora rufo-testaceous, black above, the tibiae white, rufo-testaceous below, black below and at the apex all round, the base narrowly rufo-testaceous, the tarsi black ; the hind legs black, a large mark on the base of the coxae abpve, the apex shallowly trilobate, not reaching to the middle, the basal joint of-the trochanters, a band, twice the length of the black basal part, on the basal half of the tibiae, the apical two-thirds of the ist joint of the hind tarsi, the apex narrowly black, and joints 2 and 3, except at the apex, white; the spurs fuscous. Wings hyaline, the nervures and stigma black, the apical nervures paler in tint; the areolet minute, square, the radius and cubitus almost touching, the recurrent nervure received at the apex. 8. Mesostenoideus heterospila sp. n. Bivak Island, January. Black, smooth and shining, the greater part of the head and thorax with a plumbeous hue; the metanotum from the keel to the top of the apical slope transversely striated, the mesopleurae longitudinally striated, narrowly above at the base, the striae becoming gradually wider below where they extend beyond the middle, the metapleurae more strongly striated, the striae becoming wider below, where they reach the apex; the furrow bordering the apex of the mesopleurae crenulated; the metanotal spines small. The palpi, a broad curved band on the upper eye orbits, tegulae, scutellum, 2 large transverse marks on the metanotum, between the keel and the apex, rounded on the inner side, narrowed on the lower side below, an oblique mark, twice longer than wide, on the upper half of the apex of the mesopleurae, one of the same length, but wider, and slighter narrowed above, on the top of the base of the metapleurae, a larger square one on the apex below, a broad band on the apex of the post-petiole, roundly, broadly incised at the base, the apex with a triangular incision, 2 broad marks on the middle of the 2nd segment, roundly narrowed on the innerside, a smaller one on the sides of the 3rd, more narrowed inwardly, 2 larger, wider marks, narrowed inwardly and extending almost to the centre, on the 4*, 2 similar, but narrower ones on the 7'h and the apical, pale yellow. The fore legs white, tinged with fuscous, the tibiae black to near the apex, the tarsi blackish; the middle pair white, the coxae black at the apex, more broadly so above, the black becoming obliquely narrowed, the apical joint of the trochanters, and the basal and apical of the tarsi black, the femora and the tibiae on the innerside tinged with fuscous, the hind legs black, more than the apical half of the coxae, apical joint of trochanters, apical half of basal joint of the tarsi and the 2™J, y& and 4*, white. The 6*n to 13Ü1 joints of the antennae white. Wings hyaline, the nervures and stigma black; the transverse median nervure received distinctly behind the transverse basal. 9- Length II m.m.; terebra 4 m.m. P. CAMERON. HYMENOPTERA. 227 9. Mesostenoideus parvidentatus sp. n. Alkmaar, November. Black, shining, with a slight plumbeous hue on the mesonotum, the 6* to 13H1 antennal joints, palpi, a large semicircular mark on the inner orbits opposite the ocelli, tegulae, scutellum, except the lower part of the apical slope, 2 transverse spots, narrowed on the outer edge, rounded on the inner, on the metanotum touching the spines, an oblique longish oval spot, twice longer than wide, on the upper apical part of the mesopleurae touching the striated bordering furrow, a larger squarish mark on the upper basal part of. the metapleurae, a somewhat similar one, but smaller and oblique, immediately over the hind coxae, a longish triangular spot — its basal part the longer, — on the post-petiole, a semicircular mark, with its lower apical end projecting, on the sides of the 2^, a smaller, transverse triangular mark on the sides of the y&, a large transverse mark, its outer part occupying almost the whole segment, reaching close to the middle and gradually narrowed inwardly, a large mark on the 4Ü1, its apex broadly, roundly incised to the base which is very narrow and a bell-shaped mark on the apical half of the last, whitish-yellow; the apex of the 6* and the 7* to 13111 antennal joints white. Legs black, an irregular streak down the lower side of the fore coxae, their apex narrowly, the trochanters, the lower side of the femora, the lower side of the tibiae and their base and apex above and the 2nd and 3rd tarsal joints; the middle coxae, — more broadly below than on the side, — at the base largely, basal joint of the trochanters, the greater part of the femora on the base and apex, the sides and beneath, the pale colour tinged with fuscous, the tibiae, except broadly below, and the 2°d and y& tarsal joints; the basal third of the hind coxae, a band all round near the base of the tibiae, one of the same length, but above only, near the apex and the apex of the ist and the 2nd and 3*d tarsal joints, white. Wings hyaline, the stigma and nervures black, the areolet punctiform, the ist transverse cubital nervure absent, the radius and cubitus almost meeting. 9- Length 15 mm., terebra 7 m.m. The middle of the front broadly, finely transversely striated, an indistinct keel down the centre. The central part of the propleurae and the apex more regularly and narrowly striated; the mesopleurae except above, more strongly and obliquely, the metapleurae still more strongly striated, except at the apex above; the metanotum slightly more strongly and widely striated, the lower half of the apical slope with only a few striae. Mesonotum with a plumbeous hue, the furrows narrow' but distinct, reaching beyond the middle and finely crenulated. Metanotal spines short, broad, rounded. 10. Mesostenoideus striatipleuris sp. n. Regen Island, September. Black, the palpi, the face except for a squarish black mark on the sides above, this black part being wider than the projecting lower one, a large semicircular mark on the sides of the vertex, extending from the hinder part to below the ocelli, tegulae, scutellum, a mark on the sides of the apical slope of the metanotum, covering the spines, the lateral parts wider than the top part which unites them; the latter is rounded above, narrowed at its junction with the lateral branches, which only extend to the top of the lower third, tubercles, a large 228 P. CAMERON. HYMENOPTERA. longitudinal mark on the lower part of the mesopleurae, the base rounded, the apex oblique, rounded on the top; there is a longish incision above; the basal projection is larger than the hinder, a longish conical mark immediately below the hind wings, its top wider at the apex, through sloping upwards from the base, a longitudinal conical mark on the middle of the metapleurae, nearer the top than the bottom, the base more rounded than the apex, the basal half below becoming widened above and with its apex transverse, a transverse line of equal width on the apex of the is' abdominal segment, a wider one on the 2^, its outer fourth widened obliquely at the base, a line on the slightly gradually widened outwardly, and lines on the sides of the following segments, that on the 4* much wider than the others, yellow. Legs whitish yellow, the femora tinged with fulvous, a wide irregular black mark on the hind coxae, commencing at the base below and extending obliquely to the apex above, the apical joint of the hind trochanters, the hinder femora above, the line commencing near the base and becoming wider towards the apex, the hinder tibiae all round narrowly at the base and on either side from near this basal band to the apex, the 4 front ones behind, the 4 anterior tarsi with the greater part of the basal 2 and the anterior 3 of all of them, black; the spurs blackish, Wings hyaline, the stigma and nervures black; the areolet with the outer nervure faint, but distinct, the recurrent nervure interstitial with it; it is wider at the apex than at the base; the transverse median nervure interstitial; recurrent nervure widely bullated in the middle. 9. Length 13 m.m., terebra 4 m.m. Front and vertex smooth, the latter with an irregular keel down the middle; it is shortly bordered by a band of narrow striae. Face rather strongly and closely punctured, the clypeus more shining, and more finely and sparsely punctured. Mesonotum shining, finely, somewhat closely punctured, the furrows fine, distinct. Metanotum rather strongly transversely striated, the basal area much more finely than the rest and with a smooth space at the base; the rest much more strongly striated, the striae running into reticulations; those on the top of the apical slope are stronger, wider apart and longitudinal. Metanotal spines longer than they are wide at the base, the sides margined above, the apex bluntly rounded. Abdominal petiole smooth, the 2nd segment closely punctured, the 3^ still more finely punctured. Stiromesostenus, gen. nov. Areolet represented by a short thickened transverse nervure, there being only one of them; the recurrent nervure is interstitial with it; the transverse median nervure interstitial, the transverse median nervure in hind wings broken shortly below the middle. Parapsidal furrows deep, ending at the base of the apical fourth, where they are united by a broad rounded one, bordered behind. Scutellum roundly convex, but hardly raised above the mesonotum; its sides are keeled to near the apex; the basal depression wide, deep, bearing 4 stout keels. Metanotum short, the apex obljque, with a wide rounded lateral tooth; there is a basal transverse keel; the spiracles oval, about twice longer than wide. Post-petiole not separated, the widening being gradually to the apex. Head wider than the thorax, the temples very shprt, obliquely narrowed; the occiput almost transverse. Clypeus not separated by a P. CAMERON. HYMENOPTERA. 229 furrow from the face, but the latter rises above it; its apex transverse with the sides obliquely narrowed. Labrum projecting. Eyes large, projecting, parallel; the malar space short, but distinct. Legs stout, the hinder longer and stouter than the others; the apices of the tarsal joints armed with stout spines. Antennae not thickened towards the apex. Mandibular teeth of equal size. Of the genera known to me that here described comës nearest to Erythromesostenus, Cam. irom Australia; that genus has the scutellum only keeled at the base, it has no complete transverse keels on the metanotum, the clypeus is separated from the face by a distinct furrow, its apex is rounded, not transverse and the transverse median nervure in the hind wings is broken in the middle. 1. Stiromesostenus xanthostotnus sp. n. Bivak Island, January. Ferrugineous, the antennae black, the scape on the underside brownish, joints 6—15 white, black above, the palpi white, the clypeus, labrum, malar space and mandibles except the teeth pale yellow, the rest of the head black except for a white mark between the eyes and the ocelli, extending from the hinder part of the vertex to the top of the front, its top and bottom obliquely narrowed; the mesopleurae, sternum and, less strongly, the propleurae tinged with yellow; the legs coloured like the body, the terminal joint of the 4 front tarsi and the whole of the posterior, black. Wings hyaline, the apex with a narrow cloud, the stigma and nervures black; the recurrent nervure largely bullated in the middle, united to the short thickened single transverse cubital. Cj. Length 10 m.m.; terebra 2 mm. Face closely strongly punctured, except close to the eyes, where it is finely shagreened and a smooth line above the middle; the top of the clypeus similarly punctured, the rest smooth, the apex broadly rounded. Mesonotum trilobate, its base depressed. Scutellar depression large, wide, deep; the bottom with 4 stout keels. Scutellum smooth, margined stoutly to near the apex. Base of metanotum to the keel finely rugosely punctured, the top of the apical slope more strongly rugose; the rest coarsely obliquely in the centre, more strongly transversely striated on the sides, the teeth distinct, broader than they are long, rounded at the apex; the spiracles oval, twice longer than wide. Tarsi spinose, the apices of the joints with longer and stouter spines. Cratocryptus, Cam. I. Cratocryptus fasciatipennis sp. n. Bivak Island, September. Black, the palpi, tegulae, scutellum, a large mark on the metanotum, commencing near the keel, extending to the apex, but leaving a large conical mark in the middle of the apical slope and laterally extending to the pleural keel, which it touches on the lower half, the tst abdominal segment, except for an irregular black line before the post-petiole on the sides, the base and sides below tinged with rufous, more than the apical third of the 2°d segment and the whole of the penultimate, whitish-yellow. Four front legs dark rufo-testaceous, the Nova Guinea. IX. Zoölogie. 30 »34 P. CAMERON. HYMENOPTERA. Length 9 m.m., terebra 7 mm. Neither the mesonotum nor the scutellum is quite flat, the central basal part of the former and the latter being slightly raised. Camploneurus Szép. This genus was formed in 1900. (Termés. Füzek., XXIII, 51) on a species from New Guinea, (bicolor, Szép.). Mr. H. L. Viereck, Buil. U. S. Nat. Mus., 1911, 476) states that „Cyanopterus, Haliday is the same as Camploneurus, Szépligeti, at least in part". He proposes to retain the name Camploneurus provisionally for the species that have at least the second' abdominal segment coarsely sculptured, as is the case with C. tricolor, Szép. from New Guinea. If the puncturing of the abdomen is to be regarded as a generic character then the species,; I have described here cannot be referred to Camploneurus, the abdomen on them being smooth, except the furrows bordering the area and the suturiform articulation. Cyanopterus Hal., as deflned by Szépligeti, cannot be used for my species as it has a tooth on the underside of the antennal scape and has the abdominal sutures smooth. It may be that my New Guinea species represents a y& genus. They are all pretty much alike as regards colouration, having the head, thorax, legs, and, it may be, the ist abdominal segment wholly or in part red, and the area on the 2n