BATRACHIA. 
SYNOPSIS OF ORDERS. 
A. Tail present; inferior pelvic elements not consolidated 
into a single vertical mass; proximal elements of tarsus not elon- 
gated; frontals not confluent witli parietals. 
a. Dentaries and premaxillae without teeth, covered with 
horny plates; two ethmoids, forming part of palate 
laterally; maxillaries, prefrontals, palatines, and ptery- 
goids wanting; nasals present; posterior extremities 
absent; branchiae persistent Tr achy stomata. 
b. Dentaries and premaxillse toothed; two vertical ethmoids, 
one on each side of cerebral lobes; posterior extremi- 
ties present. 
x. Maxillaries, prefrontals, and nasals wanting; ptery- 
goids and palatines present; branchiae persis- 
tent Proteida. 
y. Usual cranial bones present; pterygoids and pre- 
frontals sometimes absent; branchiae wanting 
when completely developed . . Caducibranchiata. 
B. Tail absent in adult; coccyx represented by a single 
long cyclindrical bone; inferior pelvic elements consolidated into 
a single vertical mass; proximal elements of tarsus much elon- 
gated; frontals confluent with parietals; ethmoid, a ring usually 
ossified above, surrounding cerebral lobes; limbs four; body 
short, depressed Anura. 
Order TRACHYSTOMATA. 
Family SIRENID^E. 
Premaxillae not anchylosed; two groups of vomerine teeth; 
parasphenoid edentulous; occipital condyles sessile; four persis- 
tent branchial arches; tongue free in front and on sides; eyes 
small; eye-lids not well developed; vertebrae amphicoelian ; car- 
