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REPTILES FROM RIO DE ORO, WESTERN SAHARA. 

 By dr. a. GUNTHEE, F.K.S. 



THE Triiig Museum has received last year a small colleetiou of reptiles made by 

 Mr. ]{ig-g('ubacli in the littoral district of the Kio de Oro. The physical 

 features of this district are more fully described by Mr. lliggeubach, and therefore 

 it may suffice to mention here that the " Rio de Oro " is a marine channel separating 

 a ])eninsula bearing the same name from the mainland, which for some distance 

 inland is a barren, sandy desert, without any vegetation. It was here where the 

 following eight species were collected. 



1. Geckonia chazaliae. 



Mocquard, Bidl. Mu». d' Ilixt. Nat. Paris i. 189,5. p. .311. 



This singular Gecko seems to be one of the most characteristic forms of the 

 Reptilian Fauna of this part of Africa. It is a true desert form, reminding us of 

 Phrynomma by its form and coloration, and particularly by the row of enlarged 

 tubercles which borders the back of the head. It was described in 1895 by 

 M. Mocquard from a specimen obtained 2i) kilometers inland of Cape Blanco — 

 that is, somewhat more to the north than our specimens, in tyi)ical desert country. 

 To M. Mocquard's description I have only to add that in our specimens the median 

 lower labial scute is conspicuously longer than broad, without sejjaratiug the pair 

 of small chin-shields. The largest of several individuals is 82 mm. long, of 

 which the tail takes ;iO mm. In the perfect state the tail is tapering, slightly 

 depressed at the base, annulated, covered with very small scales, and armed with 

 two longitudinal series of pointed projecting tubercles along the side, the upper 

 series being composed of the largest. Each annulns is armed with one pair of 

 tubercles. 



2. Stenodactylus sthenodactylus Licht. 



3. Tropiocolotes tripolitanus Ptrs. 



4. Varanus ^riseus Daud. 



•J. Acanthodactylus scutellatus aureus sub.sp, nov. 



A considerable number of this species were collected, and therefore it seems to 

 be the most common Lizard in this district. Specimens of this widely distributed 

 species differ greatly in the form of the snout. Although the snout is generally 

 conspicuously narrower than in the allied A. partialis, individuals do occur, 

 especially in the eastern localities, in which tlie snout is almost as wide as, and 

 not much longer than, in typical ^1. pardalis. The greatest degree of attenuation 

 has been attained by the snout of specimens from the westernmost limit of the 



