PTYCHODEIRA FEM GRATA. 345 



nal supraoculars hold the same relations towards their analogues as the 

 former : a concentric chain being observed upon the inner margin of 

 the supraocular region. The nostril perforates one single plate, more 

 towards its posterior, or inferior edge, than the anterior. The loral 

 region being considerably reduced by the declivity of the frontal 

 region, there are but one or two loral plates. The suborbital chain is 

 composed of three narrow and elongated plates, provided internally 

 with a conspicuous and sharp ridge or crest ; the longest occupying 

 the inferior rim of the orbit ; the other two, its anterior rim ; whilst 

 the posterior rim is formed by the anterior temporal scales. The su- 

 praciliary ridge is composed of five or six obliquely superposed plates, 

 smallest posteriorly. The surface of the eyelid is granular: its margin 

 being provided with a series of very small plates. The rostral is trans- 

 versely elongated and very low. The upper labials are elongated and 

 narrow, six in number, increasing in size from the first to the fourth, 

 which is the longest, then diminishing again posteriorly. The supra- 

 labial series is composed of about an equal number of similar, though 

 narrower, plates. The symphyseal is larger than the rostral, and 

 especially broader upon its middle region. The lower labials, six or 

 seven in number, are broader than the upper, diminishing gradually 

 backwards. There are four pairs of mental shields : the anterior pair 

 is the largest, contiguous upon their inner margins, whilst the other 

 pairs diverge as well as diminish in size posteriorly. A series of infra- 

 labials may be traced from the angle of the mouth to between part of 

 the first lower labial and the anterior mental shield. The temporal 

 scales are well developed, particularly the uppermost ; they are poste- 

 riorly obtuse, imbricated, and distinctly carinated. The sides of the 

 neck, which exhibit a very obsolete fold, are covered with small, 

 acute, and carinated scales. The posterior margin of the auricular 

 aperture, and the scapular region, are minutely granular. The scales 

 are rather large upon the back, diminishing in size towards the middle 

 of the flanks, being carinated and acute posteriorly. The inferior 

 half of the flanks is covered with scales similar to those which exist 

 on the belly, being only somewhat smaller, and obsoletely carinated. 

 The abdominal scales are smooth, posteriorly obtuse, and rather 

 smaller than the dorsal ones ; on the chin and throat, they do not 

 differ materially from the abdominal ones, though somewhat larger on 

 the chin than on the throat ; their posterior margin is entire : if an 

 obsolete notch is to be observed at all, it is in such as occupy the flanks. 



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