NATURAL SCIENCES OP PHILADELPHIA. 301 



size of the prefrontals. Vertical longer than broad, the anterior border straight, 

 as long a3 the occipitals. Five or six small temporals on each side. Nasal 

 plates large ; loreal longer than high. Preoculars one or two, postoculars 

 three. Superior labials eight or nine, liable to irregular subdivision ; fourth 

 and fifth, or fourth, fifth and sixth entering the orbit. Twelve inferior labials , 

 postgenials very small. Scales small, in twenty-seven rows, the median ten 

 keeled. Tail very short. 



General color of a specimen long preserved in spirits: above light brown, 

 beneath paler. The head is without markings. On the anterior part of the 

 body two black bands, two and two halves rows of scales apart, extend for four 

 times the length of the head and terminate each in a narrow elliptic annulus. 

 The latter are nearly confluent with the succeeding pair of annuli, which are 

 very narrow. These increase in breadth posteriorly until near the middle of 

 the body they become confluent on the median line, forming geminate open 

 spots; near the tail they lose the geminate form. Their whole number is 36 

 pairs, separate or united. Alternating with these is a small series of annuli, 

 which become elongate anteriorly, and finally become short black lines, paral- 

 lel to, and three scales from, the median pair. A few spots on the extremities 

 of the gastrosteges on the posterior part of the abdomen. Total length, 30 in.; 

 Tail, 3.9 lin. 



Habitat. Mexico. Mas. Acad. Nat. Sciences. 



The American genus Arizona now embraces six species ; viz. A. e 1 e g a n s, 

 jani, p 1 e u r os t i c tu s, reticulatus, deppei, and li n ea t ic o Hi s. 

 Three of these have been described by Dum. et Bibr. as belonging to their 

 genus ElapKis, i.e. Natrix Laurenli (Coluber Gthr.), but that genus is charac- 

 terized by a differently formed rostral plate, and double anal. 



Drymobius aurigulus Cope. 



Of the group Mastkophis B. & G. Scales in seventeen rows as in testa- 

 ceus, those of the median series very elongate. Crown and muzzle very 

 plane, supercilium and cantbus rostralis prominent; eye moderate, muzzle 

 more elongate than in any other species of the genus. Rostral plate rounded, 

 prominent, recurved above. Vertical elongate, posteriorly half as wide as each 

 superciliary, not in contact with preocular. Occipitals elongate, posteriorly 

 truncate. Nasals and loreals very long, the latter encroaching much on preoc- 

 ular. Three pre-, two postoculars. Superior labials eight, fourth and fifth en- 

 tering orbit; the last equal in elevation and length to the penultimate. Inferior 

 labials ten, fifth largest ; postgeneiais longer than pregeneials. 



Color above brown becoming nearly black anteriorly. Cephalic plates 

 light brown shaded with yellow. A narrow yellow band passes round the muz- 

 zle from eye to eye. A spot on the temporal region, one on the postoculars, all 

 the labials, the chin and anterior part of the abdomen bright golden; sides of 

 the neck to the fifth row of scales ditto. On the second and third rows of 

 scales of the latter region is a black band regularly interrupted at intervals of 

 about seven scales. It finally becomes continuous, and with a band upon the 

 first row almost excludes the ground color upon the posterior and middle parts 

 of the body. Abdomen dirty yellowish. 



Proportions probably similar to those of D. t a e n i a t u s ; (specimen muti- 

 lated.) 



Habitat. Cape St. Lucas, Lower California. Mr. Jus. Xantus' coll. 



This curiously marked species most resembles the D. ornatus (Masticophis 

 ornatus B. & G ) The number of rows of scales is greater ; the scales them- 

 selves are narrower; the muzzle is more elongate hence also the nasal and 

 loreal plates ; there is one more preocular, and the ultimate superior labial is 

 larger. (Smiths. No. 5793.) 



Lampropeltis boylii, var. con jnncta Cope. 



It was observed in these Proceedings, 1860, p. 255, that Cape St. Lucas speci- 

 1861.] 



