GASTEROSTEIFORMES 



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 



Syngnathus acus, L., 



Fio. 414. 

 , with subcaudal brood-pouch. (After Giinther.) 



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



with a small fin, 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 srnallaper- 



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



pouches are generally developed in the male. 



Family SYNGNATHIDAE. With a very 

 elongated body. The pectoral fins have been 

 lost in Nerophis and Gastrotoceus. The latter 

 carries its eggs in a soft abdominal mem- 

 brane, and Synynathus on its belly without 

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

 toral, abdominal, or subcaudal ventral pouches. 



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

 tropical seas ; and Eocene, Europe. Siphono- 

 stoma, Kaup., Atlantic ; Miocene, Europe. 

 Calamostoma, Ag. ; Pseudosyngnathus, K. and 

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

 Indian Ocean. 



Family HIPPOCAMPIDAE. The scutes are 

 buttressed, and immovable sideways. The 

 head is bent at right angles to the body, and ventral brood-5>buch.* (Fro 



., il and Sedgwick.) 



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. 415. 

 Male of Hippocampus sp. Brf, 



