Reptiles and Amphibians of Illinois. 383 



or continue along the side of the body. Branchial tufts crim- 

 son. Beneath paler than above, with the under side of the 

 throat and middle of the belly nearly white. Tail sometimes 

 with an orange border and generally with large submarginal 

 dark spots. 



Length from tip of the snout to p( sterior margin of vent, 

 9.25; from latter point to end of tail, 4.37. 



Occurs in running water throughout the State. Cook Co., 

 Oregon, Peoria (Brendel), Henry, Mt. Carmel (Yarrow). 



This is one of our largest batrachians, but it retains through- 

 out life many of the characters of the tadpoles of other mem- 

 bers of the order. It is often captured on hooks baited for fish, 

 and so dreaded is its bite that the line is frequently cut to let it 

 escape. It is, however, perfectly harmless. The spawning 

 season is in April and May. The eggs, Holbrook tells us, are 

 about as large as peas. It subsists on crustaceans, insects, and 

 mollusks. 



Family SIRENIDE. 



Posterior legs and the pelvic bones wanting. Anterior 

 legs with three or four digits. Jaws provided with horny 

 plates instead of teeth. Vomerine teeth in two large divergent 

 patches. No parasphenoid teeth. No eyelids. Three per- 

 sistent branchial tufts, with three corresponding free arches 

 across the branchial opening and a fourth arch bound in 

 the integument. Premaxillaries not anchylosed. Maxil- 

 laries, palatines, pterygoids, and prefrontals wanting. Occipital 

 condyles sessile. Carpus cartilaginous. Vertebrae amphicoelian. 



The family includes but two genera, both American. They 

 may be defined as follows : 



Digits three. Branchial tufts not fimbriate. With longi- 

 tudinal bands Pseudobeanchus. 



Digits four. Branchial tufts fimbriate. Without longi- 

 tudinal bands Siren. 



Siren, Linn. 



Linnseus, Act. Acad. Upsal. 1766. 

 Dum. et Bibr., Erp. Gdn., 1854, IX., p. 191. 

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