EXTERNAL ANATOMY OF INSECTS. 527 



of a neckj or a constriction of the head behind. In the 

 Orders Orthoptera, Trickoptera, Lepidoptera, Hymeno- 

 ptera, and Diptera, no instance of it that I recollect oc- 

 curs : in the Coleoptera there are many. In the Preda- 

 ceous beetles, though several have no distinct neck, yet 

 others, as Anthia, &c. have a short and thick one ; and 

 some few, as Colliuris, Agra, &c. one more pronounced. 

 Latreille has named a tribe in this Order Trachelides, 

 from the circumstance of their having; a neck: in this 

 tribe you will find the blister-beetles (Cantharis and My- 

 labris) both of the moderns and the ancients. In the 

 Hemiptera order the water-scorpions Nepa, &c. have a 

 thick short neck; and Zelus, (a kind of bug,) one longer 

 and more slender ; and, like Raphidza, the snake's-head 

 fly, which is similarly circumstanced, has the air of a 

 serpent. Other Neuroptera, likewise, have a neck; as 

 Hemerobius, Corydalis, &c. This part presents no other 

 features that merit notice. 



IV. MyoglypJiides a . — The Myoglypkides, or muscle- 

 notches, are sinuses, some shallow and some deeper, in 

 the posterior margin of the upper side of the head, to 

 which the levator muscles are affixed. They seem prin- 

 cipally confined to the Coleoptera; though, in some 

 cases at least, they may be traced in the Heteropterous 

 Hemiptera. These notches vary in number and depth 

 in different insects. Thus in Buprestis there is only one 

 deep one b : in Copris there are two shallow ones, in a 

 deep sinus separated by a small prominence c : in Elater 

 and Lamia there are also two not in a sinus ; and in Ca- 



• Plate XXVH. Fig. 1, 3—5. n'. " Ibid. Fig. 3. 



c Ibid. Fig. 4. 



