168 Dr. A. Giinther on a new Genus of West African Snakes, 



d. Nine zones round the trunk; ventrals 238, caudals 24. — One 



specimen from Bahia. 

 €. Ten zones round the trunk; ventrals 228, caudals 26. — Two 



specimens from Bahia. 

 /3. A yellow ring is half as wide as an outer black one ; one zone and 



a half round the tail. 



a. Nine zones round the trunk; ventrals 231, caudals 34. — One 



specimen from the West Indies. 



b. Ten zones round the trunk; ventrals 220, caudals 36. — One spe- 



cimen. 



c. Ten zones round the trunk; ventrals 245, caudals 33. — One spe- 



cimen from Trinidad. 



d. Fourteen zones round the trunk; ventrals 262, caudals 30. — 



One specimen from Brazil. 



2. No white cross-band before the eyes. 



06. Nasal separated from the praeocular by the third labial shield : E. 

 Gravenhorstii, Jan, founded on a single specimen from Brazil; 

 it is described as having the middle black ring twice as wide as 

 an outer one, but the figure represents it narrower. 



j3. Nasal in immediate contact with the praeocular. 



a. The black rings not confluent on the belly. 



uec. Shields of the muzzle and of the crown black, anteriorly 

 margined with yellow; thirteen zones round the body, one 

 round the tail. — One specimen from the Argentine Repubhc. 



i3/3t Muzzle and crown entirely black : E. Margravii, D. & B. 



b. The black rings of every zone confluent on the belly, and the 



yellow rings spotted with black. 



net. Ten zones round the trunk, and one or one and a half round 

 the tail; ventrals 230, caudals 22-24. — Two specimens from 

 Brazil. 



/S^. Twelve zones round the trunk and one round the tail ; ven- 

 trals 232, caudals 20. — One specimen from Brazil. 



3. Muzzle entirely white : E. frontalis, D. & B. 



II. The intervening spaces of the red ground-colour are equal in width 



to the middle black ring : E. Tschudii, Jan. 



III. The intervening spaces of the red ground-colour are narrower than 

 the middle black ring ; a white band before the eyes. 



1. Ten zones round the trunk; ventrals 221, caudals 36. — One speci- 



men. 



2. Eleven zones round the trunk ; ventrals 240, caudals 39. — One spe- 



cimen. 

 B. The three black rings of each zone equal in width to one another. 



I. No white band before the eyes : IE. Margravii, D. & B. part. 



1. Black rings not confluent on the belly. 



a. Eight zones and a half round the body, one half round the tail ; 



ventrals 222, caudals 22. — One specimen from River Capin 

 (Para). 



b. Twelve zones round the body, one round the tail ; ventrals 228, 



caudals 23. — Two specimens from Caraccas, 



2. Black rings confluent on the belly, a yellow band behind the eyes ; 



ventrals 199-213, caudals 29-37 : E. elegans, Jan, from Mexico. 



II. A white band before the eyes. 



1 . The yellow rings are narrower than the black ones ; thirteen zones 



round the trunk, one and a half round the tail. — One specimen. 



2. The yellow rings are broader than the black ones; ten zones round 



the trunk, one round the tail. — One specimen from St. Vincent's, 



