736 AFRICAN REPTILES AND BATRACHIANIS STEJNEGER. 



mcDS may show a coloration more approachiui^ ('. )i((salis than C. 

 rhomheatus. 



Causus rostratiis Guntiier (P. Z. S., 18G4, p. 115, pi. xv) is a species 

 marked like G. rhomhe((tHs, but with the rostral of G. rcsimiis. Judg'ing 

 from tlu' illustration (pioted, the iuteriiasal is broadly in contact with 

 tlie loreal, as in both of these species, and difters consequently in the 

 same manner as they from G. nmaUn. It has, moreover, only 17 scale 

 rows. In view of these facts I am unable to regard G. rostratus as a 

 synonym of G. )'esi)nus, as du Bocage has been doing (Jorn. Sc. Lisboa, 

 VIII, No. 32, Mch. 1882, p. 290). 



Gausus lichteusteim Jan (a specimen of which is in the Museum, No. 

 20805, collected by Mr. J. A. Camp at Leopoldville, Congo State), 

 ditt'ers in so many points that a comparison may be considered unnec- 

 essary; it has 15 scale rows and a blunt rostral, €ven less prominent 

 than that of G. rhomheafus. On the other hand, the coloration is some- 

 what similar to that of G. nasalls, and the internasal is widely sepa- 

 rated from the loreal. The above characters are more than sufficient 

 to separate them. 



Gausus jachsonu GtJNTHER is the latest species described (Ann. Mag. 

 Nat. Hist., (G) i. May 1888, p. 331), and in many respects the one which 

 comes nearest to G. uasalis. The coloration appears to be very similar as 

 well as the form and size of the rostral. Whether the internasal joins 

 the loreal, or not, is not expressly mentioned in the description, and 

 no figure is given, but it is said that "in (»ther respects [except rostral] 

 the scutellation is very much as in the other two sj)ecies" [G. rout rat us 

 and G. rhomheatus]. The chief character to be relied on in Dr. Gliuther's 

 description is therefore the number of scale rows, which is 23, and as 

 he had three specimens before him this alone would seem sufficient. 



The exact locality of the type of Gausus uasalis Avas not furnished 

 by the collector (Mr. W. H. Brown, of the U. S. Eclipse Expedition to 

 West Africa, 1889). However, a very sinular specimen, though larger 

 but in i)Oorer condition, was obtained by him at Cunga on December 

 25 (IT. S. Nat. Mus. No. 16074), and the type is probably from the same 

 neighborhood. This large specimen has lost the arrow-shai)ed mark 

 on the occiput, as well as the postocular streak, but the dorsal chevrons 

 are well marked. In the type both the cephalic and the dorsal marks 

 are well pronounced. 



In addition to these West African si)ecimeiis we have recently 

 received two si)ecimens collected byMr.Chanier on the Tana River (U. S. 

 Nat. IMus. Nos. 20088 and 20089), both smaller than the type ; No. 20089, 

 in fact, quite young, only 14S""" long. In the larger specimen tlie black- 

 ish color markings have nearly disapi)eared, but they are well devel- 

 oped in the young one, agreeing perfectly with the type in color, though 

 the ground color is more bluish. 



In scutellation the eastern specimens differ but very little from the 

 western ones. The internasals and loreals are (piite alike. The only 



