^^Vo'"'] PROCEEDINGS OF THE NATIONAL MUSEUM. 153 



figure), none iu coutact with orbit; uiue iufralabials, the first five lar- 

 gest; mental triauguhir, with two well-defiued concavities on the an- 

 terior border; only one pair of large, broad geneial shields, with a 

 straight anterior border joined in its whole length by the posterior 

 border of the first iufralabials, the lower border of the second infra- 

 labial only meeting the lateral border of the geneial; a small scale 

 wedged in between the geneial and the fourth and fifth Infralabials 

 probably represents the second pair of geneials. Scales nearly equal, 

 in 19 rows, those on the anterior third of the body nearly smooth, but 

 becoming gradually more distinctly keeled posteriorly; gasterosteges 

 159; anal entire; urosteges 31 pairs. Tail rather blunt. 



Dimensions. — Total length, 325™"'; length of tail from anus, 42'"""; 

 proportion of tail to total length = 1:7.75. 



Coloration {in alcohol).— White, with fifteen " seal brown" * blotches on 

 the back from head to tip of tail, becoming paler posteriorly ; the first 

 of these blotches which begins three scale rows behind the parietals is 

 of a uniform dark color, rather long and nearly hour-glass-shaped, its 

 anterior border being concave, and the anterolateral corners produced 

 to the angle of the mouth, and nearly meeting the posterior ends of a 

 broad line of dark color which runs from the upper posterior labials on 

 one side through the eye across the interorbital space down to the 

 hinder labials on the other side; the other blotches are more or less 

 square with rounded corners, the middle portion being lighter — the 

 dark color only "powdered" over the white ground — with dark borders. 

 The anterior and posterior borders wider than the lateral ones, the 

 white interspaces faintly "powdered" with brown on the sides; hinder 

 supralabials with the posterior margin dark brown ; lower surface uni- 

 form white. 



This very distinct and interesting novelty with which I wish to asso- 

 ciate the name of its discoverer, Mr. Herbert Brown, of Tucson, Ariz., 

 in recognition of his successful researches in that Territory, differs in 

 many important points from the previously described Ph. decurtatus, 

 from Lower California. It is apparently of stouter build, with a pro- 

 portionately longer tail ; the dorsal scales are decidedly keeled on the 

 posterior two-thirds of the body, while in Ph. decurtatus they are all 

 smooth; the number of gasterosteges is larger and the urosteges fewer; 

 in Ph. decurtatus the rostral seems to be thicker, and the shields on the 

 sides of the face are fewer; finally, the coloration is very different. Ph. 

 hroivni having only fifteen dorsal blotches and no lateral spots,. against 

 double the number of dorsal blotches and very pronounced lateral 

 spots in Ph. decurtatus. 



Through the courtesy of the authorities of the Philadelphia Academy 

 of Natural Sciences I have before me the type of the latter species, 

 and as the original description is meager and inadequate 1 take the op- 

 portunity to present a more detailed one. 



^Ridgway, Nomencl. Colors, pi. iii, fig. 1. 



