36 



it. Body depressed or subcylindrical. Tail filiform but 



not prehensile. Head not elevated, without spines. Stigmatophora p. 97. 

 (3. Body compressed. Tail prehensile. Head compressed 

 with a broad crest on occiput and neck, provided 



with strong spines Haliichthys p. 105. 



b. Caudal fin present. 



x. Superior cristae of trunk and tail continuous. . . . Ichthyocampus p. 90. 

 /3. Superior cristae of trunk and tail discontinuous. 

 aa. Opercular keel rectilinear, complete or incomplete. 

 Base of dorsal not elevated. 



eta. Inferior cristae of trunk and tail continuous; 

 median cristae of trunk and inferior cristae 

 of tail discontinuous. 



1. Upper profile of snout evenly continued in 



that of forehead; orbits not prominent . . Syngnathus p. 77. 



2. Snout forming an angle with the orbital 



part of the head, which is prominent . . . Corythoichthys p. 68. 

 |S/9. Inferior cristae of trunk and tail discontinuous ; 



median cristae of trunk and inferior cristae 



of tail continuous. Snout forming no angle 



with orbital part of head Micrognathus p. 74. 



bb. Opercular keel convex, bent upwards to gill- 

 opening, with radial lines. Base of dorsal elevated. 

 Inferior cristae of trunk and tail discontinuous; 

 median cristae of trunk and inferior cristae of 

 tail continuous. 



1. Edges of shields spinous ; dorsal profile of snout 

 and head spinous. Orbital part of head strongly 



prominent and sharply separated from snout. Halicampus p. IO2. 



2. All the edges and ridges of head smooth. 



a. Orbits prominent. Snout equal to postorbital 



part of head, with a median serrated keel. Tr achy r ham p hits p. 98. 



b. Orbits not prominent. Snout in indo-austra- 

 lian species equal to or longer than remaining 



part of head, without serrated keel Yozia p. 100. 



C. Brood organ a subcaudal permanent egg pouch, per- 

 manently closed by median coalescence of the lateral 

 cutaneous folds and provided with a cranial opening, 

 which can be closed by a circular muscle (Hippocam- 

 pina Duncker). 



I. Tail prehensile. Longitudinal axis of head forming 

 a right angle with axis of trunk. Praenuchal shield 

 surmounted by a coronet Hippocampus p. 106. 



