302 HALLOWELL ON SOME NEW REPTILES 



anteriorly with the preocular, and inferiorly with the superior labials the frontal is 

 much smaller than the anterior frontal ; it has immediately behind it the inter-parietal, 

 and upon the external aspect of its posterior border the parietal ; the inter-parietal is 

 a small plate resembling the frontal in form, but smaller ; the parietals are more 

 extended in the transverse direction than longitudinally ; in front they touch the 

 ocular and supra-ocular, latero-externally the frontal, and posteriorly the inter-parietal ; 

 four small quadrangular plates margin the upper lip on each side ; the eyes are 

 latero-superior placed as above mentioned ; the body is slender, of nearly uniform 

 size, somewhat thicker near the middle, covered with scales which are broader than 

 they are long, presenting a rounded margin posteriorly, somewhat smaller near the 

 head than upon other parts of the ,body ; of these scales there are twenty-nine 

 longitudinal, and three hundred and forty-four transverse rows ; there are sixteen 

 rows upon the tail ; the tail terminates in a pointed spine. 



Coloration. — (From a specimen in spirits.) The entire under surface of the animal 

 is yellow, without spots ; the back presents ten narrow black lines, extending from 

 the head to the extremity of the tail ; of these the two exterior are less distinct than 

 the rest ; the three central ones become broader toward the tail ; the intervening 

 portion is white or silvery grey. 



Dimensions. — Length of head 2 lines ; greatest breadth transversely 2i lines ; length 

 of tail 2 lines; length of body 8 inches 2 lines, (Fr.), greatest circumference 7 lines. 



Habitat. — Liberia, West Coast of Africa. Specimen in the Museum of the 

 Academy. 



General Observations. — The reptile above described, belongs to the first section of 

 the Ophidians, described by Dumeril and Bibron; viz,, the Scolecophidians, or 

 vermiform non-venomous serpents. There can be no doubt, we think, that it is new. 

 But three species of the genus OnycJiocephalus are described by them in their 

 Erpetologie generale, or Histoire Naturelle complete des reptiles, which contains 

 descriptions of all the species of reptiles known. They are the Omjchocephalus 

 Delalandii, multilineatus, and unilineatus. The first is figured in the work of Dr. 

 Andrew Smith, upon the Zoology of Southern Africa. In multilineatus the tail is 

 double in length the breadth of the head, and the body presents a series of white lines 

 upon a ground of silvery grey. In unilineatus a single black line passes along the 

 median line of the back, which is of an olive-brown color.* 



Tropidonotus coNCiNNUs. PI. xxviii., fig. 2.) 



Specific Characters. — Head slightly swollen at the temples, depressed; canthus 

 rostralis grooved ; a longitudinal yellow line running along the median line of the 

 back, including one entire row and one half of each of the adjoining rows of scales ; 



* Prooeedinga of the Acad. Nat. Sci., May 30th, 1843. 



