ORISMOLOGY. 331 
by the shield of the prothorax. Ex. Hymeno- 
ptera. 
2, Covergp (Tectum). When it is quite concealed by 
the prothorax. 
3. AREATE (Areatum). When it is larger than the 
prothorax, and terminates towards the wings in 
two oblique areas, inclosed by a ridge often crown- 
ed anteriorly with little teeth. Ex. Zibellulina. 
Prats IX. Fic. 7. g* a. N.B. The space between 
these areas is fitted with a membrane capable of ten- 
ston and relaxation, which -in flight causes them to 
approach to and recede from each other. 
. AMPLECTENT (Amplectens). When posteriorly it is 
so curved as to form a large sinus which embraces 
the Dorsolum. Ex. Vespa L. Puate 1X. Fic. 
ll. g’. 
5. Pyonetic (Phoneticum). When its posterior an- 
gles, approaching the wings, cover the vocal spira- 
cles*. Ex. Htymenoptera. 
nN 
8. DORSOLUM. 
1. THoracirorm (Thoraciforme). When it forms the 
principal part of the upper surface of the trunk. 
Ex. Bombus, Apis, Vespa L., &c. Puate IX. 
ie lelZ. * 
y. SCUTELLUM. 
— 
. Distinct (Distinctum), When it is separated from 
the dorsolum by a suture. Ex. Hymenoptera, 
Diptera. Puate IX. Fic. 11, 19, &¢. #. 
. CoaLite (Coalitum). When it is not separated 
aS) 
“ Chabrier Sur le Vol des Insectes. Mem. du Mus. t. viii, 58. 
