Key to the indo-australian species of 

 Hemirhamphus. 



I. Pectorals not as long as head from tip of upper jaw 

 to branchial opening. 



A. Triangular part of upper jaw longer than broad. H. georgii p. 147. 



B. Triangular part of upper jaw broader than long. 



1. Base of ventrals midway between frontborder 

 or hindborder of eye and base of caudal. 



a. Head from tip of upper jaw to branchial 

 opening 3.2 in trunk. Caudal with a black 



border H. unifasclatus p. 149. 



b. Head from tip of upper jaw to branchial 

 opening 3.5 3.7 in trunk. Caudal with a 



black border H. gaimardi p. 150. 



c. Head from tip of upper jaw to branchial 

 opening 3.7 4 in trunk. Tips of caudal 



black H. melanurus p. 151. 



2. Base of ventrals more backwards, at most 

 midway between head and base of caudal, gene- 

 rally nearer to base of caudal than to head. 



a. Anal with 14 16 divided rays. Dorsal and 

 anal opposite to each other or nearly so. 



Praeorbital as long as eye H. balinensis p. 152. 



b. Anal with 9 13 divided rays. Praeorbital 

 shorter than eye. 



. Cylindrical or nearly so, the breadth of 



the body equal to or 1.2 in its height. 



Anal with n 13 divided rays. Dorsal 



and anal opposite or nearly so. 



a'. Length of lower jaw beyond extremity 

 of upper jaw 6.6 9.8 in length. 

 Origin of ventrals midway between " 

 base of caudal and head . . H. quoyi p. 154. 



b' . Length of lower jaw beyond extre- 

 mity of upper jaw 4.5 5.2 in length. 

 Origin of ventrals nearer to base of 



caudal than to base of pectorals. . . H. du3stimieri p. 155. 

 |3. Compressed, the breadth of the body 



going 1.4 1.8 in its height. Anal with 



9 10 divided rays. Origin of anal oppo- 

 site to 5th dorsal ray. 



