GA S TEROS TE 7 FORMES 



415 



processes. The pectoral radials are very small, with a row of distal cartilages 

 (Fig. 413, D). The pelvic fins are absent in the adult, though traces of 



Fig. 414. 

 Syngnathus. acus, L., $, with subcaiidal brood-pouch. (After'Giinther.) 



them appear in the embryo Nerophis (Huot [233]). The tail is attenuated 

 with a small tin, or it is prehensile and finless {Nerophis, Hippocampus). 

 The skeleton is to a great extent cartilaginous, and the notochord 

 largely persistent, though constricted. The 

 visceral skeleton is much reduced, and the 

 four gills are considerably modified. The 

 lamellae have lost their pectinate character, 

 become less numerous, and acquired a 

 rounded shape (Fig. 413, B, C). The 

 branchial openings are narrowed to smallaper- 

 tures dorsally placed (Fig. 413, A). Brood- 

 pouches are generally developed in the male. 



Family Syngnathidae. With a very 

 elongated body. The pectoral tins have been 

 lost in Nerophis and Gastrotoceus. The latter 

 carries its eggs in a soft abdominal mem- 

 brane, and Syngnathus on its belly without 

 pouch; but in others the eggs are carried in pec- 

 toral, abdominal, or subcaudal ventral pouches. 



Syngnathus, L. (Fig. 414), temperate and 

 tropical seas ; and Eocene, Europe. Siphono- 

 doma, Kaup., Atlantic ; Miocene, Europe. 

 Calamostoma, Ag. ; Pseudosyngnathus, K. and 

 S. ; Eocene, Europe. Nerojjhis, Kp.; Atlantic, 

 Indian Ocean. 



Family Hippocampidae. The scutes are 

 buttressed, and immovable sideways. The Male of Hippocamp 

 head is bent at right angles to the body, and ventral brood-pouch. (From Claus 

 the tail is curved and prehensile. There 



is a ventral ovisac. The ' Sea-Horses ' are among the most specialised of 

 fish in general structure, and sometimes they are further provided with 

 branching dermal processes simulating seaweed {Phyllopteryx). 



Hippocampus, Leach (Fig. 415) ; temperate and tropical seas. 



Phyllopteryx, Sw., and Gastrotoceus, Kp. ; Pacific. 



Fig. 41." 



