294 



REPORT OF NATIONAL MUSEUM, 1898. 



The bead above is covered by small polyhedral or i)yramidal plates, 

 except oil the supraorbital region. The occipital plate is large and 

 polygonal, the edges are raised, and it has also a central tubercle; it 

 is situated in the midst of small plates, of which there are two series 

 to the supraorbitals. There are two small vertical plates in line, but 

 anterior to these there is no regular arrangement, the most symmetrical 

 specimen showing one plate in the center of a circle of seven others, 

 and then four median in line to rostral. There are, however, three 

 series of hexagonal plates above the eye parallel to the inner border of 

 small plates; anterior to which the plates on the supraorbital region 

 are smaller than elsewhere on the upper surface of head. The eyelids 

 are granular, with a series of longer flat plates along the edge. The 



Fig. 33. 



HOLBROOKIA MACULATA MACULATA BAIRD AND GiRARD. 



Fort Kearny to Laramie, Wyoming. 



Cat. No. 9366, U.S.N. M. 



loral and supralabials are small and tubercular. The nostrils are supe- 

 rior, situated in a single plate, except anteriorly, but closely surrounded 

 by others which appear to form their outer border. 



The scales of the back and sides are all excessively small, almost 

 granular. Those on the central line of the back for six or eight scales 

 being rather larger (by an insensible gradation) than the others, and 

 are quite distinctly but obtusely carinated ; the lateral scales around the 

 base of the tail are all similar to the dorsal. The scales immediately back 

 of the head are smaller than elsewhere on the back. About one hundred 

 and twenty-five scales can be counted, as nearly as may be, from head to 

 above arms. The belly scales are rhomboidal, decidedly larger than any 

 of the dorsal; they are rhomboidal and smooth. Those in front of arms 



