in the Collection of the British Museum. 355 



across the interorbital space, the latter sometimes confluent 

 with a triang-ular occipital spot. A deep-brown black-edged 

 band from the eye to the angle of the mouth. Belly with more 

 or less distinct, marbled cross bands. The dorsal bands are 

 sometimes very light in the middle, having the appearance of 

 double bands. One variety is almost entirely brownish black 

 above. 



This species comes from Rio Janeiro : it is the most slender 

 species of the genus, and has the body distinctly compressed 

 and the ventral shields obtusely keeled. 



Tropidonotus ferox. PI. VI. fig. F. 



Scales strongly/ keeled, in twenty-one or twenty-three series; 

 anterior frontals very small, pointed ; eye surrounded by a ring 

 of small shields ; maxillary teeth in a continuous sei'ies, slightly 

 increasing in length posteriorly. 



Habit stout ; head somewhat depressed, of moderate width 

 and length ; eye rather small. Nostrils obliquely directed up- 

 wards ; the nasal shield is entire above the nostril, and divided 

 below. Rostral shield small, rather broader than high, scarcely 

 reaching to the upper surface of the snout; anterior frontals 

 very small, longer than broad, pointed in front, in contact with 

 the rostral ; posterior frontals small, about one-third the size of 

 the vertical, broader than long. Vertical five-sided, with the 

 outer edges pai-allel; occipitals rather small, rounded behind. 

 Loreal rather lai'ge. Eye surrounded by six or seven small shields 

 (the supraorbital not included), two of which may be considered 

 as prseoculars, and two as postoculars. Nine upper labials, 

 the fifth of which is below the middle of the eye. Temporals 

 1 4- 2 -f- 3, the first being rather large, the others scale-like. 

 Veutrals 146 ; anal bifid ; subcaudals 72. 



Upper parts dark brown or brownish black; sides lighter, with 

 a row of subtriangular black spots. Each ventral shield with a 

 black base ; subcaudals entirely blackish. 



Fernando Po. Total length 19^ inches, the tail measuring 

 5^ inches. 



Besides the specimen in the British Museum, I have seen a 

 second, larger one, alive, in the Zoological Gardens, Regent's 

 Park. It measures about 2 feet, and is darker in coloration. 

 It is very fierce, and, when driven into a corner of its cage, will 

 raise the anterior part of the body and extend its gape, ready to 

 strike. It is very nimble ; and I never succeeded in catching it 

 without being bitten. 



The discovery of this snake proves the existence of Tropido- 

 notus in West Africa — a fact new to our knowledge of the geo- 

 gi'aphical distribution of Ophidians. 



