236 Phthinobranchii 



numerous in all warm seas, mostly living in shallow bays among 

 seaweed and eel-grass. The muscular system is little developed 

 and all the species have the curious habit of carrying the eggs 

 until hatched in a pouch of skin under the belly or tail; this 

 structure is usually found in the male. 



The Solenostomidae. The Solenostomida of the East Indies 

 are the most primitive of these fishes. They have the body 

 rather short and provided with spinous dorsal, and ventral 

 fins. The pretty species are occasionally swept northward to 

 Japan in the Black Current. Solenostomus cyanopterus is a 

 characteristic species. Solenorhynchus elegans, now extinct 

 (with the trunk more elongate), preceded Solenostomus in the 

 Eocene of Monte Bolca. 



The Pipefishes: Syngnathidae. The Syngnathidce are very long 

 and slender fishes, with neither spinous dorsal, nor ventral 

 fins, the body covered by bony rings. Of the pipefish, 

 Syngnathus, there are very many species on all northern coasts. 

 Syngnathus acus is common in Europe, Syngnathus fuscum 

 along the New England coast, Syngnathus californiense in 

 California, and Syngnathus schlegeli in Japan. Numerous 

 other species of Syngnathus and other genera are found further 

 south in the same regions. Corythroichthys is characteristic 

 of coral reefs and Microphis of the streams of the islands of 

 Polynesia. In general, the more northerly species have the 

 greater number of vertebrae and of bony rings. Tiphle tiphle 

 is a large pipefish of the Mediterranean. This species was 

 preceded by Tiphle albyi (Siphonostoma} in the Miocene of 

 Sicily. Other pipefishes, referred to as Syngnathus and Cala- 

 mostoma, are found as fossils in Tertiary rocks. 



The Sea-horses: Hippocampus. Both fossil and recent forms 

 constitute a direct line of connection from the pipe-fishes to the 

 sea-horses. In the latter the head has the form of the head 

 of a horse. It is bent at right angles to the body like the head 

 of a knight at chess. There is no caudal fin, and the tail in 

 typical species is coiled and can hardly be straightened out. 

 Calamostoma of the Eocene, Gasterotokeus of Polynesia, and 

 Acentronura of Japan are forms which connect the true sea- 

 horses with the pipefish. Gasterotokeus has the long head 

 and slender body of the pipefish, with the prehensile finless 



