NATURAL SCIENCES OP PHILADELPHIA. 101 



gion, and spreading in the posterior lower labials of the same color, 

 yellow bordered above. Labials, mental and gular regions yellow, with 

 blackish spots and vermioulations. A blackish spot on each end of every 

 gastrostege anteriorly ; posteriorly they become confluent with those of the 

 sides. Abdomen yellow, immaculate. 



Habitat. Paysondu, Uraguay. Mus. Smithsonian, from Mr. H. W, Kennedy. 



The genus here called Rhadimea, has afforded me considerable perplexity, 

 standing as it does in near relationship with Coniophanes, Coronella, Lygophis, 

 and Diadophis. Its type is the Taeniophis vermiculaticeps, which I 

 indicated in 18G1* as belonging to an unnamed genus. Coronella decorata 

 Gthr., is a second species. This I formerly placed provisionally in Diadophis, 

 partly on account of its two preocular plites. A specimen from Vera Cruz, 

 has, however, but one, and the dentitition is not isodont, but syncranterian, as 

 Giinther describes, though of a weak type. The same arrangement is exhibited 

 by the vermiculaticeps and poecilopogon. The tail of the d e co- 

 rat u s is relatively much longer than that of the vermiculaticeps; the 

 p o e c i 1 o p o g o n is rather intermediate in this respect. The dentition dis- 

 tinguishes this genus from Coniophanes ; the pattern of coloration is the same, 

 and the scale pores are equally wanting. The general form is rather more 

 slender. If we ignore the difference in dentition, these serpents might be re- 

 ferred to Lygophis, where some species are of similar scutellation, proportion, 

 and coloration. The closest accordance with Coronella in structural charac- 

 teristics exists, but the species are much more slender, and the head is more dis- 

 tinct. If we unite them with that genus, Coniophanes, its closest ally (through 

 C. imperialis) must follow, and if so, then Lygophis and Liophis, whose 

 connection with Dromicus is well known. Coronella anomalais probably 

 Lygophis rutilus, with abnormal simtellation, and the dentition described, 

 as syncranterian ; it seems to be diacranterian in the specimens described 

 under the last name ; other specimens have or have not the interval anterior 

 to the last long tooth. Whether this species is a Lygophis or a Rhadinaea, or 

 whether it renders the two inseparable, must be left at present to future in- 

 vestigation. Its form is more slender than Coronella. 



If Coronella, as Giinther left it in his " Catalogue," could be defined tren- 

 chantly from genera leading to such distant connections, it would be well to 

 accept it ; but to me it is a union of natural groups, which, as being the most 

 definable, may be called genera. They are Coronella proper, Macroprotodonf, 

 Coniophanes, Rhadinaea, Larapropeltis, and perhaps others. 



In the system of the Erpetologie Geoerale, the species of Rhadinaea would 

 enter the section of Leptophis, characterized by smooth scales. 



Rhadinaea ob t u s a, Cope. sp. nov. 



Muzzle broadly rounded, rather short. Head small. Tail one-fourth the 

 total length. Head plates shorter than in the poecilopogon; outlines of ver- 

 tical slightly concave. Eight superior labials, loreal nearly square, encroach- 

 ing on the single preocular, which does not reach the vertical. Two postocu- 

 lars touching one temporal. Scales in nineteen longitudinal rows. Total length 

 41-25", the tail 8-75." 



Above olive brown ; ends of gastrosteges and sides, including border of 

 fifth row of scales, blackish ; a median dorsal band embracing one and two 

 half rows of scales, which disappear on the tail. Beneath saffron yellow ; a 

 blackish dot on the end of each gastrostege anteriorly. Chin and labial regions 

 immaculate. 



Habitat. Paysondu, Uraguay. Dr. Kennedy's collection furnished also that 

 rare species Tomodon o c e 1 1 a t u s. This serpent looks much like a Tachy- 



* Proc. A. N. S., p. 74. 



t It would prove interesting if the Coronella b r e v i s Gthr., should be found to possess 

 the elongate anterior mandibular teeth of Macroprotodon. 



1863.] 



