49 



Crocodile, and C. marglnatus of Southern Africa. Of these, accord- 

 ing to the best recent authority, namely Dr. Gray, the characters 

 are, — . 



C. vulgaris. — "Head elongate, triangular, flat, smoothish above, 

 narrow, tapering at the sides, nearly twice as long as the width of 

 the head behind ; muzzle at the noteh nearly two-thirds the width 

 of the forehead, at the niuth tooth as wide as half the distance be- 

 tvveen the eyes and nostrils ; forehead flat, with nearly parallel sides." 



C. marginatus. — " Head elongate, triangular, rather convex, 

 rounded, sides slightly svvollen behind the noteh, half as long again 

 as the width of the head behind ; muzzle at the first noteh as wide 

 as the forehead, and at the ninth tooth as wide as two-thirds the 

 distance between the eyes and nostrils ; forehead deeply eoncave, with 

 the sides high, prominent and nearly parallel ; dorsal platės very 

 strongly keeled." 



I shall no\v describe generally the škulis which I brought home, 

 giving the measurements of four of them ; from which it will be 

 seen, that while in various prominent points they more resemble the 

 latter, yet in proportional measurements they approach more nearly 

 to, while not altogether agreeing witli, C. vulgaris, thus sho-wing that 

 in many characters they are intermediate, and thus either lowering 

 these two into mere varieties, or what is, I believe, more probable, 

 establishing for themselves specific characters. 



" Head elongate, oblong, somevvhat triangular, rather convex, espe- 

 cially posterioriy, rounded, upper surface rough, sides distinctly 

 swollen behind the noteh ; length more than twice the width of head 

 behind ; forehead slightly eoncave, sides not prominent, converging 

 anteriorly ; muzzle at noteh nearly two-thirds the greatest width of 

 forehead ; at the ninth tooth more than two-thirds the distance be- 

 tween the eye and nostrils." 



Measurements. 



No. 1. No. 2. No. 3. No. 4. 

 in. in. in. iu. 



Extreme length 26 2A\ 22^ 21 



Greatest vvidth behind 12J 12 11 1 lOį 



Distance from eye to nostril. .10^ 10 9 8^ 



Breadth at ninth tooth 7f H 6i 5į 



Breadth at noteh . . ., A\ 3| 3f 2f 



Width of forehead, anteriorly. 5 4^ 4^ 4 



Width of forehead, posterioriy 6^ 5 f fi\ 5 



Extreme length oflowerjaw .. 29 27 24^ — 



The proportions of all these correspond almost exactly, and I have 

 ascertained the proportional measurements of a smaller one to be the 

 šame, although from its being in pieces and not yet put together, I 

 have not time to take the exact dimensions. They show the Croco- 

 dile from the Binue to be proportionally longer than C. vulgaris, and 

 much more so than C. marginatus, to be in form of upper surface 

 and of forehead near the latter, but without the prominent sides to 



No. CCCXXX. — Proceedings of the Zoological Society. 



