RHYTIDODEIRA OXYCEPHALA. 355 



conspicuously larger than the rest of the same name ; they are, as 

 usual, polygonal, transversely elongated ; in the concentric chain, 

 they are subequal, and slightly larger than in the longitudinal series, 

 which interposes between the middle ones and the supraciliary chain. 

 The latter is composed of six, thin, tiled laminae, immediately above 

 the eye, and a thicker one upon the side of the snout. A subpyriform 

 nasal, posteriorly perforated by the nostril, would be placed within the 

 supraciliary ridge, if the latter was extended forwards ; it is contigu- 

 ous, by its narrow extremity, to the rostral. There are two exiguous 

 supranasals, placed one in advance of the other, and three very small, 

 unequal postnasals. The inferior edge of the nasal plate is contiguous 

 to the supralabial series. 



On the loral region, we observe but two small plates, that we can call 

 by that name, an anterior one, subtriangular, extending upwards in 

 front of the supraciliary ridge, and might be numbered as one of that 

 series, and a posterior one, somewhat smaller, pentagonal, or polygo- 

 nal. Two anteorbitals : the uppermost is situated in advance of the 

 elongated suborbital ; the lower one, elongated, is placed immediately 

 beneath the upper, smaller than the latter, and does not enter into the 

 orbit. At the posterior rim of the orbit, there are two small, ecaly 

 plates, behind the suborbital; the rest is formed by the anterior scales 

 of the temporal region. The supralabials, five or six in number, are 

 narrow, elongated, and somewhat smaller than the labials : the ante- 

 rior one is smaller than the rest, which increase in size to the fifth or 

 sixth, the latter not extending as far as the suborbital. 



The rostral is quite narrow, transversely elongated. The upper 

 labials, six or seven in number, increase in size posteriorly to the fifth 

 or sixth ; the last is less regularly linear than the rest in the series, 

 being also generally the smallest. The symphyseal is hemidiscoid, 

 and larger than the rostral. The lower labials, five on either side, 

 gradually diminish in size backwards, being anteriorly larger than the 

 upper labials. We observe one series of infralabials, and four pairs of 

 mental shields : the anterior pair, as usual, contiguous upon their 

 inner edges. The scales, on the remaining portion of the chin and on 

 the throat, are subequal, smooth, subrhomboid, posteriorly einarginated, 

 and somewhat less developed than on the abdomen. The temporal 

 scales are rather large and smooth. The scales are subequal on the 

 back and abdomen ; on ' the flanks, smaller ; the former keeled and 

 acuminated ; the latter subacuminated and obsoletely keeled ; the 



