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Show APPENDIX C.- REPTILES, 865 PHRYNOSOMA MOPESTUM, Girard. PL. ftl. Fio. 4- 8. The most striking characters by - which this species can be. distinguished from its congeners consists in the want of the peripheral abdominal row of pyramidal scales, and also in the slight development of the scales on the upper region of the body, which loses considerably that rough appearance so characteristic in the other species. The tail affords another character peculiar to Phr. modestum; it tapers more suddenly, and is perfectly cylindrical beyond the dilated portion of its base. The head has the same general appearance as in Phr. j> latyrhino$ 9' although it is not so much truncated, and still leser so in the pdult than in the young ( fig. 6). The vertex is more circular than in the latter, but the occipital and temporal spines do not differ much in the two species. The nostrils have'the same position within the superciliary ridge, ( fig. 7). The lower jaw exhibits one row of large plates, with one single series of very small pne? above, forming the edge of the jaw, while we have seen two rows of the latter in Phr. platyrhinos. BeloW the head the scales are exceedingly small- much- smaller than in Phr. platyrhinos. They are uniform among themselves^ except a row of a little more conspicuous ones forming one series along the inside of the maxillary plates ( fig. 5). The scales on the belly are smooth, subquadrangular, and larger than in any other species. ' The femoral pores are smaller, and even more apart than in Phr. platy rhinos, but there is no separation on the middle line of the belly, and the series from both sides meet in advanee of the vent, forming a convex curve turned backward ( fig. 8). "• ' • . •; • The coloration is uniform yellowish- brown above, with two lateral patches of black on the sides of the neck. Transversal and narrow bands of black are se. en on the tail. The black spot seen on the left side of fig. 4 is accidental; that is, it exists on the specimen figured, but. is not found on any others which have since pome to hand. Brought from the- Rio Grande, west of San Antonio, by General Churchill. A series of adult specimens were collected from San Antonio to El Paso, by the party under Colonel J* D. Graham, late of the United States and Mexican boundary survey. |
