EtJTAENIA INFERNALIS. 149 



of a triangular aspect. The postfrontal extends to the upper half of 

 the loral region. The vertex plate is subhexagonal, quite broad, 

 maintaining its width posteriorly. There are seven upper labials ; the 

 third and fourth situated beneath the eye ; the fifth and sixth are the 

 largest of the series. The lower labial plates are ten in number. The 

 anterior meets its fellow under the chin, and thus interposes itself 

 between the triangular symphyseal and the anterior pair of mental 

 shields. The second labial is the smallest of all; they increase in size to 

 the sixth, which is the largest, diminishing again from the seventh, 

 posteriorly. The posterior pair of mental shields is longer and more 

 slender than the anterior pair, which are contiguous upon their inner 

 edge, where three or four elongated scales may be observed, inter- 

 vening between the posterior pair. 



The tail, which is very slender, constitutes about the fourth of the 

 total length. 



The dorsal scales are disposed upon nineteen longitudinal rows ; the 

 external row, though larger, is carinated like the rest. On the tail the 

 scales are likewise carinated. There are one hundred and sixty-six 

 abdominal scutellae, and eighty-five pairs of subcaudal ones. 



As to the coloration, there is a vertebral line of yellowish-white, 

 composed of one and two half rows of scales, on each side of which is 

 a blackish stripe, not encroaching upon the light colored stripe along 

 the second and third lateral rows of scales. Above the latter the black 

 is interrupted by about one hundred and ten subtriangular spots of 

 reddish-yellow or reddish-white. The abdomen and exterior row of', 

 dorsal scales are greenish-white, tinged posteriorly with a slate hue. 

 A minute black spot, more or less covered by the incumbent scales, 

 may be seen on each abdominal scutella, near its extremity. 



Log. — From the neighborhood of Sacramento River, California. 



Plate XIV, fig. 11, represents Eutaeriia infernalis, size of life. 



Fig. 12, is a profile of the head. • 



Fig. 13, an upper view of the same. 



Fig. 14, the head, seen from beneath. 



Fig. 15, exhibits the dorsal scales. 



Fig. 16, the vent and surrounding scutellae. 



Figs. 12-16, are magnified about one diameter. 



38 



