198 STNGNATHID^. 



from the others. The vent is below the middle of the dorsal fin. 

 Broad irregiilar dark-brown bauds across the back. 

 Australia. 



a. Type of the species, female, 11 inches long. Freycinet's Har- 



bour. Voyage of the ' Herald.' 



b. Young. Australia. 



14. ACENTRONURA. 



Acentronura, Kaup, LupJiob): p. 18. 

 Trunk slightly compressed, composed of thirteen (twelve ?) rings. 

 Shields without tubercles. Occiput compressed into a crest, with- 

 out coronet. Tail prehensile, finless *. Pectoral fins. The edge 

 of the trunk is continuous with that of the tail. Egg-pouch as in 

 Hil^pocamjms. 

 Japan. 



1. Acentronura gracillima. 



Hippocampus gracilissimus, Schley. Faun. Japon. Fuiss. p. 274, pi. 120. 



fig. 7. 

 Acentroniu-a graciUima, Kaup, Lophohr. p. 18. 



Dorsal fin with seventeen rays, standing on four rings, two of 

 which belong to the tail. Snout short. 

 Japan. 



15. HIPPOCAMPUS t. 



Hippocampus, Leach, Zool. Misc. 1814, p. 103. 



Trunk compressed, more or less elevated, composed of from ten to 

 twelve rings. Shields with more or less prominent tubercles or 

 spines. Occiput compressed into a crest, terminating at its supero- 

 posterior corner in a prominent knob (coronet). Supraorbital, 

 temporal, and humeral regions with prominences. Tail prehensile, 

 finless. Pectoral fins. The males carry the eggs in a sac at the 

 base of the tail, opening near the vent. 



Inhabitants of all the seas of the temperate and tropical regions. 

 They are pelagic fishes which attach themselves to seaweed or other 

 floating substances, and are liable to be carried by currents to 



* Traces of a small "caudal" are mentioned in Schlegera description; but 

 this is evidently a slip of the pen for " anal." 



t 1. Hippocampus algiricus, Kaup, Lophohr. p. 13. — Algiers. 



2. marginalis, Kaup, Lophohr. p. 15. — Mexico. 



3. faseicularis, Kaup, Lophohr. p. 15. — Mexico. 



4. fuscus, Euppell, N. W. Fische, p. 143. taf. 33. fig. 3.— Eed Sea. 



6. Syngnathus hippocampus, Mitch. Trans. Lit. df- Phil. Soc. N. York, i. 

 p. 475; Hippocampus brevirostris, Storer, Report, p. 167; Hippo- 

 campus Ludsonius, Bckay, Fauna N. York, Fish. p. 322, pi. 63. fig. l71 

 (bad) ; Storer, Mem. Am. Acad. ii. p. 491, and viii. p. 416, pi. 33. 

 fig. 4 ; Lockicood, Amer. Nat. 1867, p. 225. — Atlantic coasts of the 

 United States. 



6. Hippocampus gracilis, Gill. Proc. Ac. Nat. Sc. Philud. 1862, p. 282. 



— California. 



7. ingens, Girard, U. S. Pac. B. R. Explor. Fish. p. 342. — California. 



