Mr. Bell on a new Genus oflgunnidce. 207 



Iguanas, they are distinctly trilobate.* Tlie nostrils which are 

 oval and somewhat projecting, are placed immediately in front, 

 about half an inch above the mouth. The eyes are situated 

 about the same distance behind the nostrils. The ears are 

 small, and the membrana tympani, as in the rest of the family, 

 quite superficial. The throat does not appear to have any consi- 

 derable pouch, but my specimen is so badly stuffed that it is im- 

 possible to ascertain the exact natural size and figure of this part. 

 The body is covered with small scales, which are rather larger 

 upon the back, and of a pointed conical form, so as to render 

 the surface scabrous. Immediately behind the occiput, com- 

 mences the cervical crest, consisting of a series of about twenty 

 spines, closely arranged, of which the central ones are very long 

 and large, but those beyond the first ten becoming suddenly 

 smaller, and terminating almost insensibly in the commencement 

 of the dorsal crest, which consists of similar spines ; those of the 

 anterior part being long, rounded and straight, but becoming re- 

 gularly shorter, flatter, and more curved backwards, to the middle 

 of the tail, where they gradually en crease a little in length and 

 breadth, and then again diminish to the termination. They are 

 about 120 in number, exclusive of the cervical, of which 80 may 

 be considered as belonging to the back. The legs are strong and 

 large, and the toes differ from those of any others of the family 

 in being nearly of equal length. The claws are remarkably 

 strong, and much hooked. There are 24 femoral pores on each 

 side. The tail is round, except towards the extremity, where it 

 is flattened at the sides. It is covered wilh scales of considerable 

 size arranged in rings ; those of the upper part being the largest. 

 The general aspect of the animal gives the idea of great 

 strength. The only specimen I have seen, and which is in my 

 collection, has become so faded. that little can be said about its 

 natural colour, except that here and there indications may be 

 perceived of the usual mottled appearance of the Iguanas, 



* Supp. PI. xn. (I. 



