THE LIFE HISTORY OF THE SEA-HORSES (HIPPOCAMPIDS). 



By Theodore (Jill, 



Hotioniry Associate hi Zoology. 



In the ordinary works on tishes or natural history very little is said 

 about the inttn-esting- little fishes popularly known as sea-horses. 

 Many details, however, have been published in isolated notes or Ijuried 

 in general articles, which only one familiar with ichthyological litera- 

 ture would be likely to know about or even to find by using the 

 current bil)liographies. For the benefit of those interested in the 

 group the notes here presented, l^rought together for a general work 

 on tishes, are published. 



I. 



The sea-horses (Hippocampids) vary in form, but all are compressed 

 and incapable of flexing the body sideways to any very considerable 

 extent, the plates having extensions which are buttressed against cor- 



Ta,. 



•9'^ JSSn. 4^ 



Fiu. 1.— Bkoad-nosed Pipe-fish (Siphonostoma typhle). Skull frum side showing elongation 



OF FACIAL BONES, small MOUTH AND JAW BONES, AND ABSENCE OF PREOPERCLE. (AFTER SCHAFF. ) 



B. 0., Basioccipital; Ect., Ectethmoid; Kt/i., Ethmoid; E.t: O., Exoccipital; Fi:. Frontal: Hw., 

 Hyomandibilak: ./. ()., Infraorbital; Mil., Mandibular; M.c, Maxillary; Op., Operculum; 

 Pa.. Parietal; PL, Palatine; Pin.r., Premaxillary; PL, Pterotic; Qh., Quadrate; ,S'. 0., Supra- 

 occipital; Sjih.. SpiiENOTic; Si/m.. Symplectic. 



responding ones of the preceding and succeeding plates, thus prohibit- 

 ing any decided laN'ral movements. The tail is more or less curved 

 downward, and in typical forms highly prehensile; it is quadrangular 

 in section. 



The head in front of the eyes, or snout, is prolonged in a tubiform 

 manner as in the pipe-lishes (Syngnathida?), and the mouth and jaws 

 are small and at the end of the tube; the preopercle is absent and the 

 operculum greatly enlarged. 



Proceedings U. S. National Museum, Vol. XXVIII-No. 1408. 



805 



