VOL. XIII, 



] PROCEEDINGS OF THE NATIONAL MUSEUM. 185 



Deserijition of type specimen. — Head uarrow, snout long, pointed ; head 

 shields swollen ; two pairs of iuternasals, the posterior in contact with an- 

 terior supraocular 5 one pair of i >re iron tals; nasal separated from rostral ; 

 a supranasal; a j)OStuasal; a loreal, pentagonal, not higher than wide, 

 and separated from prefrontals; a preorbital; two suborbitals, the 

 posterior very lon-g ; one very large upper postorbital and two minute 

 lower ones ; ten and twelve supralabials ; sides of neck covered with 

 granular scales; lateral fold, commencing below the ear opening; 

 nuchal scales not keeled, in ten longitudinal rows ; dorsal scales of 

 medium size, in sixteen longitudinal rows, the four median obtusely 

 keeled, the next two on each side with the keels still less pronounced 

 and the remainder smooth ; forty-six transverse dorsal rows ; ventrals 

 smaller than dorsals, in twelve longitudinal rows; [tail reproduced]. 



Color (in alcohol) above uniform "tawny-olive" with interrupted 

 transverse bands of black dots on the sides, the scales with the dots 

 being margined posteriorly, more or less distinctly, with whitish; under 

 side dull pale clay-color, with irregular black dots on flanks and throat. 



Dimensions of type. 



Millimeters. 



From snout to veut 121 



From snout to ear opening 27 



From snout to lore limb 38 



From axilla to groin 67 



Greatest width of head 18 



Fore limb 27 



Hind limb ...: 34 



Unfortunately, the exact locality where the type of this species was 

 collected is not known ; all that the record book contains is " Mexican 

 Boundary." It was evidently obtained by one of the surveying parties 

 of the United States and Mexican Boundary, but the original number 

 having become obliterated, it was re-entered in 1877 and the original 

 label — or what remained of it — destroyed. 



The present species belongs to the same group as the foregoing, 

 having "three pairs of shields between the frontal and the. rostral," or 

 in other words, " two pairs of internasal scuta." It differs from B. im- 

 hricata, however, in the greater number of dorsal rows, both longitudi- 

 nal and transverse ; in the obsolete carination of the dorsal scales ; in the 

 exclusion of the ioreal from the prefrontals ; in the smaller size and 

 greater number of the temporals, and in the narrower and more elon- 

 gated shape of the head. It has the sixteen longitudinal rows of dorsals 

 in common with B. planifrons Bocourt, but the head shields are 

 swollen and the other characters which separate it from B. imbricata 

 also distinguish it from B planifrons. B. rndicolUs is still farther re- 

 moved by the low number of the transverse dorsal rows, the strong 

 carination of the nuchal shields, and the contact of the nasal with the 

 rostral. 



