1901.] NATURAL SCIENCES OF PHILADELPHIA. 495 



and lateral angles of the frontal plate. There is the same number 

 of dorsal spots as in the type. 



The fourth example is 472 mm. long (tail 67); scales in 31 

 rows, of which 15 are keeled; ventrals about 240; subcaudal& 

 about 63. The color is very similar to the type, but less intense, 

 and there are but 20 dorsal spots on the body, with 8 on the tail. 



In all the young individuals the light portion of the dorsal 

 stripes, continuing the lateral arms of the H-shaped spots, is less 

 distinct than in the adult, and the whole under surface is pearly 

 white, with indications of the cloudy markings under the tail ; the 

 carination of the dorsal scales is so indistinct that it is hard to 

 determine its exact extent. 



The bright colors and the strong contrasts shown in life by the 

 adults, render this one of the most beautiful of North American 

 snakes. The pattern on the dorsal region is simply the extreme 

 development of the tendency toward longitudinal extension of the 

 corners of the spots, which is shown at times in some other species, 

 such as C. obsoletus confinis, which occasionally exhibits even the 

 neck -bands. It is also suggested on the forepart of the body in 

 0. lineaticollis Cope, but from these it differs widely in scutella- 

 tion, and its real relations are with the section of Coluber repre- 

 sented by the Mexican C. triaspis and C. mutabilis, which tend in 

 the direction of the nearly related genus Pityophis through P. 

 vertebralis, from which, however, it is abundantly distinguished by 

 the generic characters and by the curious fact that the color shading 

 is completely reversed, the spots in C. subocularis being black 

 anteriorly and fading toward the tail, while in all species of 

 Pityophis the exact opposite occurs. 



