1895.] BA.TBACHIAXS fBOM ADEX. 657 



the length of the frontal and one half of the praefrontal. In 

 T. ohtusus and T. rhmopoma the supraocular is excluded from 

 contact with the praefrontal by the praeocular, while in T. guen- 

 theri it touches the praefrontal and excludes the praeocular from 

 contact with the frontal. There are nine upper labials, but 

 exceptionally, asymmetrically, ten ; but in the other two species the 

 number is unusually ten, and exceptionally eight, nine, or eleven. 

 The third, fourth, and fifth, or exceptionally the fourth and fifth 

 labials enter the orbit, whereas the fourth, fifth, and sixth in 

 T. obtusus, and the third, fourth, and fifth, fourth and fifth, or 

 the fourth, fifth, and sixth in T. rldnopoma enter the eye. The 

 chin-shields are narrower and more elongated than in these two 

 species. There are 21 scales round the body, but 23 in T. obtusus 

 and T. rUnopoma. The anal, in this species and in T. rldnopoma, 

 is invariably single, but it is always divided in T. obtusus. Ventrals 

 235-274 ; in T. rhmopoma 268-280 ; aud in T. obtusus 257-272. 

 The caudals in T. guentheri are 66-72 ; in T. rhinopoma 76-82 ; 

 and in T. obtusus 66-81. 



The general colour is exactly as in T. obtusus in the majority of 

 the specimens, but in one specimen from Muscat the body-colour is 

 greyish with numerous narrow black markings, interrupted bands, 

 becoming indistinct posteriorly, and separated from each other by 

 narrow whitish interspaces or lines. The upper labials are slightly 

 orange-yellow with blackish margins ; ventrals pure white. 



This species was obtained some years ago at Muscat by Dr. 

 Jayakar, and my collector who accompanied Mr. Bent on his 

 expedition to the Hadramaut brought back two specimens. 



The invariable presence of an unlivided anal and of 21 rows of 

 scales round the body of these Eastern Ai-abian snakes seem to 

 entitle them to specific rani. At the same time, if a single speci- 

 men had shown any tendency to division in the anal, or had there 

 been any variation in the number of the body-scales, I should have 

 hesitated to follow the course I now adopt and would have regarded 

 them as varieties of T. obtusus. 



To bring out the differences that exist between the three species, 

 I append the following tables (pp. 658, 659). 



I have much pleasure in connecting Dr. Giinther's name with 

 the species. 



" These two specimens were obtained in a sun-dried brick wall at 

 Lahej. They were found within a few inches of each other, and 

 each of them had breakfasted on a sparrow. In one the bird was 

 quite fresh, and had evidently been recently caught, while in the 

 other it was partially digested." 



21. EcHis CABTKATA, Schneider. 



1 2 • ]Jahej. 



Snout to vent 436 ; tail 50. V. 159 ; A. 1 ; C. 30. Scales 28 ; 

 upper labials 10. Scales round eye 17 and 18. Nasals 2. 



" This, I believe, to be the only venomous snake found at Aden, 

 where, and also inland, it is not uncommon." 



Peoc. Zool. Soc— 1895, No. XLII. 42 . 



