NATURAL SCIENCES OF PHILADELPHIA. 369 



Coloration. Above blackish brown, darkest anteriorly. Very indistinct, 

 pale transverse bands are apparent. They are irregularly oblique, and separa- 

 ted by intervals of two or three scales wide. Superior and inferior labials 

 more or less completely margined anteriorly with yellow ; geneial and gular 

 plates spotted irregularly with the same. General color beneath a peculiar 

 stone brown. A darker shade occupies the centres of the gastrosteges as far 

 as the vent. This is almost excluded anteriorly by a central series of trans- 

 versely elliptical yellow spots, one near the anterior border of each gastrostege. 

 These become narrower, and broken, and upon the posterior two-thirds of the 

 belly are almost lost. There is a very indistinct row of smaller spots upon 

 each side of it anteriorly. 



Habilat. ? Key West. Mus. Comparative Zoology, Cambridge, 

 This species should be compared with T. sipedon, T. celaeno and 

 T. valid us. It differs from the first in the number of rows of scales, and 

 from all three in the form of the muzzle and coloration of the lower surface. 



Thamnophis scalaris Cope. 



Head narrow, elevated, the profile sloping in front, muzzle obtuse. General 

 form moderately slender, the tail a little less than one fourth the total length. 

 Superciliary and vertical plates elongate, the lateral borders of the latter 

 straight and convergent. Occipitals elongate. Loreal plate higher than long^ 

 one pre-, three postoculars. Superior labials eight, fourth and fifth entering the 

 orbit. Inferior labials ten. Anterior geneials longer than posterior. Scales 

 in nineteen rows, not emarginate, the external smooth. Gastrosteges 143 ; an 

 entire anal; urosteges 59 pair. 



Coloration. Beneath, and upon the first row of scales, dark, ashy olivaceous, 

 the latter frequently black at their bases. Second and half the third row of 

 scales a little paler. The vertebral, and the borders of one row on each side 

 of it, yellowish. The color of the remainder of the upper surface is brown, 

 anteriorly shaded with olivaceous. This is crossed from the lateral to the 

 dorsal stripe on each side, by vertical bars, black, or deep brown bordered 

 with black, numbering from the head to the origin of the tail, about sixty. 

 There is a pair of large spots just behind the occipital plates, and one involving 

 the temporals and the whole of the occipitals, its anterior border trilobate and 

 produced upon the vertical and superciliaries. A short yellowish vitta extending 

 from the posterior angle of the former plate along the occipital suture, repre- 

 sents a confluent pair of occipital spots. 



Habitat. Jalapa, Mexico, found by Sr. R. M. De Oca. Mus. Academy. Pre- 

 sented by Thos. B. Wilson. M. D. 



Arizona Jani Cope. 



Head not very distinct, tapering. Rostral plate rounded, presenting an 

 obtuse angle between the prefrontals, Post-frontals bent upon the sides of 

 the head. Vertical longer than broad, the lateral borders much converging, 

 posterior angle obtuse. Occipitals longer than vertical, subdivided as in 

 Pityophis sp. Nostril between the nasals ; loreal plate longer than high. One 

 preocular not reaching the vertical, three postoculars. Superior labials eight, 

 fourth and fifth entering the orbit, inferior labials twelve, sixth largest. Post- 

 geneials shorter than pre-genials. Scales of the body in twenty-seven or nine 

 rows, the central thirteen keeled. Tail short. 



Coloration. Above, a pale yellowish brown, browner on the crown and 

 muzzle. A series of quadrate dorsal spots extends throughout the whole length, 

 involving from thirteen to seventeen medial rows. Anteriorly they are sepa- 

 rated by spaces eight scales wide, but these intervals diminish posteriorly. 

 There is a lateral series of spots which alternate with those of the dorsal row, 

 and are sometimes confluent with others, which form a series along the tips of 

 the gastrosteges posteriorly. Anteriorly the dorsal intervals are divided by a 

 transverse series of three small spots, which are probably sometimes confluent. 

 These markings are all black anteriorly ; posteriorly, they are shaded with 



I860.] 



