b PROF. HUXLEY ON THE SPECTETC AND GENERIC 



The other mandibular teeth are received between the maxillary 

 teeth. The symphysis of the lower jaw does not extend beyond 

 the level of the seventh or the eighth mandibular tooth. The 

 premaxillo -maxillary suture may be either straight or strongly 

 convex backwards. The divided vomers do not appear in the 

 palate. The posterior nares look more or less backwards, and 

 are transversely elongated. The supra-temporal fossae are always 

 open, and the feet are distinctly webbed. The dorsal scutes are 

 not articulated ; and tliere are no ventral scutes. 



Two genera, Crocodilus and Mecistops, are distinguishable in 

 this family. 



Genus 4. Crocodilus. 



The teeth are always strong and very unequal, the strongest in 

 the upper jaw being the tenth. The mandibular symphysis does 

 not extend beyond the level of the sixth tooth. There are usually 

 six cervical scutes, in two rows, or forming a rhomb, and separated 

 by a distinct interval from the tergal scutes. There are 18 or 19 

 teeth above, and 15 below, on each side. 



1. Crocodilus vulgaris. 



As Cuvier has remarked, it is extremely difficult to find good 

 distinctive characters for all the species of this genus. My first 

 difficulty was to ascertain the precise characters of tluit species 

 which has been misnamed vulgaris, inasmuch as I could find 

 neither in the British Museum, nor in the Museum of the Eoyal 

 College of Surgeons, any authentic skeleton or skull of this, the 

 so-called Nilotic Crocodile. This difficulty subsisted up to the 

 time that the chief statements contained in the present essay were 

 laid before the Linnean Society ; but since then I have been en- 

 abled, by Dr. G-ray's permission, to examine the skull of a small 

 stuffed specimen, brought to this coxmtry from Egypt by Sir 

 Gardner Wilkinson, and to study the splendid entire skeleton of a 

 Crocodilus vulgaris in the Christchui'ch Museum at Oxford, pre- 

 sented to that Institution by the gentlemen who shot it on the Nile, 

 and set up with great care under the auspices of my friend Dr. 

 EoUeston, Lee's Reader in Anatomy and Curator of the Museum. 

 Fortunately the entire skin has been preserved ; so that this is the 

 most complete record of the hard parts of any individual crocodile 

 with which 1 am acquainted, besides being, so far as I am aware, 

 the only authentic entire skeleton of Crocodilus vulgaris in this 



