xii 
Plate 32. 
Plate 32. 
Plate 33. 
TABLE OF THE PLATES. 
INSECTA. Vol. 1V. Page 
No. 2.—Parts of the skeleton of DyTIscus. 
Fig. 1.—Internal portion of the bead. a, a.--The two ridges which pro- 
ceed from the throat and enclose the cerebellum. ¢.—The 
tentorium. d.—A band, consisting of two halves, upon which 
the anterior portion of the cerebellum rests. e, e.—Two 
hooked processes, which encompass the esophagus in front of 
the cerebrum. f,/.—A horny ridge to which the labrum is 
attached. g.—The tongue. h.—A horny semicircular bone, 
to which the tongue is attached. 0, b.—The orbits. 
Fic. 2._The prothorax seen from beneath. 0b, b.—The omia. 
Fig. 3.—The prosternum from behind. a, a—The jugularia. 0b, b.—In- 
ternal processes of the prosternum, 
Fig. 4.—The omium seen from the surface. 0.—The external surface. 
b*,—The reflexed margin which lies against the surface of the 
pronotum. 
Fig. 5.—Prosternum from the side. .—The internal processes. 
Fig. 6.—Coxe, trochanters and femur of the intermediate leg. a— 
Audouin’s trochantinus. 
Fiz. 7.—Meso and metathorax from above. 
Fig. 8.—The same from beneath 
Fig. 9.—Mesosternum exposed, so as to show its internal processes. E.— 
The body of the vertebra whence the arches proceed which 
encompass the nervous cord. b, b, are the transverse pro- 
cesses. a.—The processus spinosus, consisting of two halves. 
Fig. 10.—Anterior wing of the scapula (D). 
Fig. 11.—Fosterior wing of the scapula (D*). b.—The reflexed margin 
which forms the suture with that of the anterior wing. 
Fig. 12.—The connate coxe seen from the front to exhibit the process 
springing from them. 6, b —-The anterior processes. 4, @, 
—The posterior, with their furcate branches**. 
No. 3.—Portions of the skeleton of BuPREsTIs MARIANA. 
Fig. 1.— Prothorax from beneath. A, A.—Reflexed margin of the pro- 
notum. B.—Prosternum. b, b.—The small round plates 
which correspond to the anterior wings of the scapule in 
Carasusand Dytiscus. 
Fig. 2.—The same from the front. a, a.—The jugularia. 
Fig. 3.—Prosternum from the side. 
Fig. 4.—Upper view of the meso and metathorax. 
Fig. 5.—The same from beneath. 
Fig. 6-8.—Mesosternum and scapule in their natural situation. 0.— 
Mesosternum (E, E). 
Figs. 7, 8.—Anterior wings of the scapule (D, D). 
Fig. 9.—Prosternum from within. a, a.—Internal processes. 
Fig. 10.—Metathorax from within, 0b, b.—The anterior teeth. 
The posterior. 
Fig. 11.—The same from the side. 
Fig. 12.—Meso and metathorax of HisTER CADAVERINUS seen from beneath. 
S.—First abdominal segment. 
Fig. 13.—The same from above. 
a, a.— 
Fig. 1.—Oryctres CHEevrovartil, Guer. 
Fig. 2,_AGACEPHALA FURCATA, Guer, - - 7) ld 
Fig. 3.—ScaRap mus MENTOR, Guer. 4 5 
Fig. 4.~Anatomical details of ScAaRABZUS GEDEON, Fab. 
