408 ATTEMPTED DIVISION OF BRITISH INSECTS. 



StIRPS. — SiRLCINA. 



Natural Order. — Sirecites. 

 Larva hatched from eggs deposited in the wood of the fir-tree, some- 

 times two or three hundred in a cluster, cylindrical, with six 

 rudimental articulate legs ; head corneous ; paratelum incrassated ; 

 gnaws the timber, making a bore, in which it lives, the exact size 

 of its body. Pupa changes in the same situation. Imago, with 

 antennae filiform, attenuated exteriorly, composed of fifteen to 

 thirty joints, the number varying in ditferent individuals of 

 the same sex and species ; mandibles strong, trifid ; maxillae 

 rather elongate, soft, flexible, obtuse, their feelers very minute, 

 exarticulate ; labium somewhat triangular ; ligula short, entire, 

 dilated ; feelers three-jointed, the terminal joint long and incras- 

 sated ; ocelli three ; wings ample, with many strong nervures ; 

 prothorax fully developed, broader than the head, its anterior and 

 posterior margins concave ; the following segments fully and 

 equally developed ; ovipositor exserted, composed of three setae. 

 Inhabits fir-plantations. Sirex, ( Tremex.) 



Natural Order. — Xyphidriites. 



Larva perfectly without feet. Inhabits and lives on the dead or 

 dying wood of various trees. Pupa changes in the same situ- 

 ations. Imago, with antennas composed of seventeen or eighteen 

 joints, gradually attenuated towards the apex ; mandibles small, 

 with four distinct teeth ; maxillae short, obtuse, their feelers 

 biarticulate ; labium short ; ligula, minute, entire ; feelers four- 

 jointed ; ocelli three ; head orbicular, large ; prothorax very long, 

 slender, and neck-like ; the remaining segments of uniform size ; 

 the oviduct of the female exserted, covered above by a sheath- 

 like appendage. Inhabits posts, decayed willows, &c. flying in 

 the sunshine. Xyphidria. 



Natural Order. — Xyelites. 



Larva perfectly without feet. Feeds in the wood of fir-trees, mak- 

 ing channels, as in the two preceding Orders. Pupa changes in 

 the same situations. Imago, with antennse twelve- jointed, the 

 basal and second joint short, the third very long, and the nine 

 following very short, together scarcely equalling the third in 

 length, elbowed twice, at each end of the long joint ; mandibles 

 moderately long, acute, and dentate internally ; maxillae with the 

 blade small, obtuse, the galea biarticulate, the feelers very long 

 and four-jointed ; labium short, ligula hitherto undiscovered, 



