17. 

 CRCESUS SEPTENTRIONALIS. 



Order Hymenoptera. Fam. Tentliredinidae Lat. 



Type of the Genus Tenthredo septentrionalis Linn. 



CutEsus Leach. Nematus Jur., Lat. Tenthredo Linn., Fab. 



Antenna; inserted between the eyes, simple, in both sexes longer 

 than the body (especially in the females), rather thicker in the 

 middle, and tapering towards the apex, hirsute, 9-jointed, first 

 joint short, second very short, the following long, and decreas- 

 ing in length to the apex. (I.) 



Labrum exserted, pilose and ciliated, transverse quadrate, convex 

 at the sides, rounded and slightly emarginate before. (2.) 

 Mandibles exserted, robust, depressed, acute, with one internal 

 tooth towards the apex. (3.) 



Maxillic narrow and corneous at the base (4. a.), dilated in the 

 middle, and produced into a tooth on the internal edge (c.) ; apex 

 membranaceous, and appearing ovate externally, from the edges 

 curving inward : Palpi long, inserted near the centre of the exter- 

 nal side, 6-jointed, first joint shortest, fourth and fifth longest, 

 sixth nearly filiform, (b.) 



Mentum quadrate, dilated and emarginate before (5. a.) ; Palpi 

 4-jointed, irregular, the third being the thickest, (b.) 

 Lip membranaceous, 3-lobed, the centre narrow and dilated at 

 the apex, side lobes somewhat hemispherical, striated towards 

 their apex, thickened at their margins and ciliated. (5. c.) 



Clypeus broad, emarginate. Ocelli 3. Abdomen sessile, short, cjjlin- 

 dric in the male, deflexed in the female. Oviduct not exserted, com- 

 posed of two lamellce, which are serrated. Superior wings witli the 

 marginal cell complete, and 4 submarginal cells. Tibite of hinder 

 legs dilated at their apex. Tarsi b-jointed, first joint the longest, 

 very much dilated and compressed iti the posterior legs, as is shown 

 in the coloured fgure. Claws unidentate internally, Pulvilli in the 

 centre. (8. a fore-leg.) Larva unth 20 membranaceous feet. 



Septentrionalis Linn. Syst. Nat. 2. 926. 36. Fab. Ent. ISyst. t. 2. 

 p. 1 19. n. 56. 

 Black, shining) head and thorax slightly punctured, pubescent, 

 a pale yellow spot on each side thescutellum, third, fourth, fifth, 

 sixth and seventh segments of the abdomen in the male, and 

 third, fourth, fifth, sixth, and aspot on the seventh in the female, 

 briglit brick colour j base of thighs, tibiye and tarsi in the 4 an- 

 terior legs ochraceous, base of tibiae and coxte in posterior legs 

 whitish. Superior wings pale, ferruginous towards the centre. 



Li the Author's and other Cabinets. 



