APPENDIX C. — REPTILES. 353 



is proportionally large, and so is the lower loral plate, as there 

 exists a second loral above the first, much smaller than any of 

 those of the orbital circle. A specimen of H. simus examined by 

 us has shown a second similar small loral on one side of the head, 

 while on the other it evidently did not exist, so that it may prove 

 either not to be constant in JI. nasicus, or to be likewise found 

 in other species of the same genus. The rostral plate is directed 

 upward, as in IT, simuSy having the same general shape as in the 

 latter. , 



The tail has the same proportions with regard to the body as in 

 H, platyrhinoSy that is about the sixth of the entire length. The 

 eyes are considerably smaller than in H. platyrhinos, as we have 

 compared specimens of both species, having the same length and 

 size of body. The only specimen of H, nasicus which we have 

 seen is not a foot long, so that we have had to compare with it 

 the young of H, platyrhinos. Now, if our H. nasicus be im- 

 mature, it is the young of a species which differs from those already 

 known of the genus, as shown by the very great difference in size of 

 the eyes, and those other characters which we have just described. 



In coloration, our species resembles more that of IT. platyrhinos 

 than that of H. simus. The ground colour appears to be the same. 

 There are in both species three rows of blackish-brown patches, 

 bordered with a line of light yellow or white; but while these 

 patches are elongated in H. platy rhinos, they assume a more circular 

 shape in £[, nasicus, although there is no regularity or sym- 

 metry about them. Two indistinct and much smaller rows exist 

 on the sides. The lower part of abdomen and tail is almost en- 

 tirely black. The throat and lower surface of head are unicolor, 

 of the same hue as the ground colour of the body above. On the 

 occiput, immediately behind the occipital plate, there is a lan- 

 ceolated patch, and on both sides of this a much greater irregu- 

 larly oval one. Two brown stripes are seen on the top of the 

 head, one over the anterior half of the eyes, extending vertically 

 to the mouth, and another over the posterior half of the eye, hence 

 obliquely backward, forming over the temples an elongated but 

 much broader patch than in H. platyrhinos and H. simus. 



This species was collected in Texas by General Churchill: a 

 specimen is preserved at the Smithsonian Institution. 



23 



