192 FOSSIL REPTILES. 



Cuv. Lacerta crocodilus, Linnaeus. Crocodilus Niloticus 

 Daud.) has, notwithstanding its ancient celebrity, been almost 

 continually mistaken by those modern naturalists who have 

 attempted to distinguish the species of this genus. Laurenti, 

 and even Blumenbach, have taken for it the palp ebrosus ; and 

 Schneider, for the sderops. This has chiefly proceeded from 

 the very detestable figures generally given by Egyptian travellers 

 of this animal, and the slender authentication of most of the 

 specimens dispersed through the different cabinets of Europe. 

 To the researches of Geoffroy we are indebted for the first 

 establishment of precise notions on this subject. 



In the true crocodile of the Nile, the length of the head is 

 double the breadth. The sides are in a general direction, nearly 

 rectilinear, and the head thus represents an elongated isosceles 

 triangle. The foramina with which the cranium is pierced are 

 large, and broader than they are long. The muzzle is rugged 

 and uneven, especially in aged individuals, but has no par- 

 ticular projecting ridge. Immediately behind the cranium, on 

 a transverse line, are four small isolated scales, with ridges. 

 Then comes the large plate of the nape, formed of six scales 

 with ridges ; then two scales a little separated ; and afterwards 

 the transverse bands of the back, almost always fifteen or 

 sixteen in number. The first twelve have each six scales and 

 six ridges ; the three bands between the thighs have only four 

 each. 



All these ridges are nearly equal, and moderately pro- 

 jecting. There is, moreover, on each side, a longitudinal 

 range of seven or eight ridged or carinated scales, not so 

 much united to the assemblage of the others. The lateral 

 ridges of the tail only commence to become prominent on 

 the sixth band, and to form two crests ; these unite on the 

 seventeenth or eighteenth band, and there are yet twenty- 

 eight more to the end of the tail. 



The equality of the scales, of the ridges, and of their number 

 in each band, and their position on two longitudinal lines, 



