4. OSTEOLiEMrs. 5. ALLIGAXOU. 280 



stronger on the others. Fingers with a rudiment of weh ; outer toes 

 hardly half-webbed. Scales on upper surface of liinljs keeled ; no 

 cncmial crest. Adult uniform blackish ; young yellowish brown 

 above, profusely dotted and spotted with black, and with broad 

 black cross bands on the body and tail ; ventral shields black and 

 yellow. 



Total length 1 metre 70 centim. 



Sierra Leone to Ogowai. 



a. Yg., spii'. Old Calabar. A. Murray, Esq. [P.]. 



(Type of "^C. froutatus.) 



h, c. Ad. & hgr., skulls, Old Calabar. A. Murray, Esq. [P.]. 



without lower jaws. 



(J. IlgT., stffd. " River Bouny. Dr. Forsyth [P.]. 



e. Ad., stffd. W. Africa. 



f, (J. IlgT. & yg., spir. W. Africa. 

 h. Yg., skel. W. Africa. 



5. ALLIGATOR. 



Alligator, part., Cuvier, Ami. Mus. x. p. 30 (1807); Diim. ^- liibr. 



m. p. 03 (1836) ; Strauch, Sijn. C'rocod. p. !J (1800). 

 Champsa, part., Waf/ler, Syd. Amph. p. 140 (I8.']0). 

 Alligator, (rrai/, Cat. Tort. ^r. p. 00 (1844) ; Huxley, Journ. Linn. 



Soc. iv. p. 3 \1800) ; Gray, Cat. Sh. llept. ii. p. 28 (1872). 



17 to 20 upper and 18 to 20 lower teeth on each side; fourth 

 maxillary tooth longest ; fourth mandibular tooth fitting into a pit 

 in the upper jaw. Snout rather short ; nasal bones forming a 

 septum dividing the nasal aperture; suprateraporal fossic small. 

 Splenial bones not entering the mandibular symphysis, which ex- 

 tends to the fourth tooth. A dorsal shield formed of six or eight 

 longitudinal series of juxtaposed, keeled, bony scutes ; gular aud 

 ventral scutes without or with thin ossifications. 



North America and China, 



Synojisis of the Species. 



The broadest transverse series of dorsal 



scutes composed of 8 scutes ; four large 



nuchal scutes ; upper eyelid bony an- 

 teriorly ; fingers webbed ; end of tail 



strongly compressed and crested .... 1. mississippiensis,]). 2d0. 

 The broadest transverse series of dorsal 



scutes composed of 8 scutes ; two large 



nuchal scutes ; fingers free ; end of tail 



little serrate above, scarcely compressed 2. Jielois, p. 290, 

 The broadest transverse series of dorsal 



scutes composed of 6 scutes ; six large 



nuchal scutes; upper eyelid entirely 



bony ; fingers free ; end of tail strongly 



compressed and crested 3. sinensis, p. 291. 



