1854.] 101 



the others, and channelled anteriorly; 13 rows of scales, four upon the back 

 carinated, the marginal row near The abdomen larger than the others. Of this 

 species there are five specimens in the, collection of the Academy, three 

 from Dr. Savage, and two fully grown from Dr. Ford. These specimens illus- 

 trate very well the inconstancy of certain plates about the head in serpents. 

 In one the loral plates are entirely absent, the posterior frontal passing down to 

 join the superior labial plates ; in a second of the smaller specimens there are two 

 lorals on each side ; in a third there are two on one side (the left) and one on 

 the other ; in one of the larger specimens there are two on each side, and in the 

 other, two on the left and one on the right.* Wagler, in his definition of the 

 characters of the genus Dryophis states that there is no loral plate, the posterior 

 frontals passing down along the side of the head, and coming in contact with 

 tbe superior labials. 



Causus rhombeatus, Wagler. Natur. System, der Amphib. p. 172. 



Naja rhombeata, Schlegel. Physiognomie des serpens, Vol. ii., p. 483, pi. 

 xvii, figs. 12 and 13. 



Sepedon rhombeatus, Lichtenstein. Berlin. Dub. Verz. 1823, S. 106. 



Scheuzer. Phys. Sacr. t. 717, p. 1. 



Vipera V. nigrum, Cuvier. Reg. Anim. T. ii., p. 92, n. 4. 



Distichurus maculatus, Hallowell. Journ. Acad. Nat. Sci. p. 8, pi. 19 

 (young). 



The genus Distichurus was based, very improperly, upon a single specimen ; 

 and the characters in that were not of sufficient importance to establish a genus. 

 The plates toward the extremity of the tail are not constantly single. In 

 one out of four specimens which we have, they are bifid. In Crotalus the plates 

 toward the extremity of the tail are sometimes bifid, and in Trigmocephalus 

 also. 



BUFO MACULATUS, nob. 



Syn. Bufo cinereus. Proc. Acad. Nat. Sci., Vol. ii., p. 169. The name 

 cinereus has long been applied by Schneider, Daudin, Merrem and others to the 

 Bufo vulgaris of Europe. Bufo maculatus resembles somewhat Bufo pan- 

 therinus, but differs from it, according to the description of Dumeril and Bibron, 

 in the size of its tympanum, the breadth of which is considerably larger than 

 the length of the upper eyelid. The form and arrangement of the markings 

 differ greatly from those in the plate of Ruppel. 



The Herpetology of Africa has as yet been but too imperfectly studied to 

 enable us to comprehend the geographical distribution of the reptiles of this vast 

 continent. The labors of Dr. Smith have left but little to be desired for the 

 illustration of the southern part of it, and Ruppell has given good dpscriptions 

 and drawings of a number of reptiles in N. Africa and Abyssinia. These, with 

 the great work on E<*ypt, and the late production of M. Bianconi, on the Natural 

 History of Madagascar, constitute the most reliable sources of information 

 appertaining to this subject. Let us hope that our own government will do for 

 the natural history of Western Africa what the English government has done 

 for that of the Southern portion of this great continent. 



The reptiles common to both Northern and Western Africa, so far as we 

 know, are Agama colonorum, Chamasleo dilepis (bilobus) Kinixis belliana 

 Echidna arietans, Naja haj.,var. black, Vipera (cerastes) nasicornis, the genera 



This inconstancy is observed in other genera. In Hydrus pelamoides the 

 frenal shield observed by M. Schlegel was not present in four individuals, ex- 

 amined in the Straits of Malacca : in all Hydri the shields of the head are liable 

 to considerable individual varieties of form (Cantor)* "Hydrus bicolor 

 Schneider a frenal shield has been observed in some individuals, but it was 

 absent in that examined in the Straits of Malacca, nor does it exist in the speci- 

 mens in the Museum of the Asiatic Society." p. 135. "In Dryinus prasinus, 

 Reinwardt, there are two, sometimes three frenals on each side." p. 83. 



* Catalogue of Reptiles inhabiting the Malay Peninsula and Islands, collected or observed \y 

 Theodore Cantor, Esq., M.D., Bengal Medical Service, 1847. 



9 



