336 ORISMOLOGY. 
3. Cerviculate (Cerviculatus). When the prothorax 
is elongate, attenuate, and distinguished from the 
Antepectus by no suture ; so as to form a distinct 
and usually long neck. Plate III. Fig. 6. 
4. Evanescent (Eva?iescens). When no distinct pro- 
thorax is discoverable or it is only represented by 
membrane. — Ex. Most Hi/menoptcra, Diptera, &c. 
5. Margin ate [Marginatus). When an impressed 
line or channel separates the edge of the protho- 
rax from the rest of its surface, and so forms a 
margin. — Ex. Harpalns, &c. 
6. Immarginate (Lnmarginatus). When it has no 
such margin. — Ex. The TUiyncophorons beetles. 
7. Explanate {Explanalus). When its sides are so 
depressed and dilated as to form a broad margin. 
— Ex. Necrophorns, Silpha. 
8. Emarginate {Emarginatus). When a segment of 
a circle is taken out of its anterior part for the re- 
ception of the head. 
9. Ambient (Ambiens). When this sinus is so large 
as to receive the whole head. — Ex. Chilocorus. 
10. Circumambient {Circumambiens). When its sides 
are elongated anteriorly and curve inwards, their 
ends lapping over each other and the head, so as 
to form a circle round the posterior part of the 
latter, and leave a space open for the eyes to see 
objects above them. — Ex. Heleus. 
11. Clypeate (Ch/peatus). When it quite covers and 
overshadows the head. — Ex. Lampyris, Cassida, 
Cossyphus. 
12. Cucullate (Cucullalits). When it is elevated into 
a kind of ventricose cold or hood which receives 
