6 
NORTH AMERICAN BATRACHIA AND REPTILIA. 
pus cartilaginous; metacarpals five. Head elongate; tail com- 
pressed. 
Toes four; color uniform Siren. 
Toes three; with longitudinal bands or stripes. 
Pseudobranchus. 
Genus Siren, Linn. 
1. S. lacertina , Linn. Great Siren. Color dusky, approach- 
ing to black, with numerous white or yellowish spots; abdomen 
purplish; eleven inches. Austroriparian region, North Carolina, 
Mexico, and Northeastern lUinois. 
Genus Pseudobranchus, Gray. 
2. P. striatus , LeConte. Striped Siren. Color dusky, 
with a broad yellow or brown stripe on each side; abdomen 
speckled with brownish white, and with two longitudinal stripes 
paler than those above; nine inches. Georgia. 
Order PROTEIDA. 
Family PROTELD^E. 
Premaxillae not anchylosed; vomero-palatine teeth; para- 
sphenoid edentulous; occipital condyles sessile; three persistent 
branchial arches; tongue large and fleshy, free in front and on 
sides; eyes small, distinct; eyelids none; vertebrae ampliiccelian; 
carpus and tarsus cartilaginous; metacarpals three; head elongate; 
trunk short and thick; toes four on each foot. 
Order C ADUCIBKANCHIATA. 
Synopsis of Families. 
A. Teeth on anterior or outer margin of palatines. Pre- 
frontals and pterygoids present; carpus and tarsus cartilaginous; 
vertebrae amphicoelian. 
a. An axial cranial bone in front of ethmoid, and one 
forming palatal surface in front of parasphenoid; parie- 
tals prolonged laterally, not reaching prefrontals; 
premaxillae anchylosed; occipital condyles pedicellate; 
a single gill-cleft on each side Amphiumidce. 
b. No anterior axial cranial bone; parietals and prefrontals 
prolonged, meeting and embracing frontals; premaxil- 
laries separated ; occipital condyles sessile; gill-clefts 
