498 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



prehensile tail are so unlislilike that it is no wonder some of the early 

 writers suggested their relationship to insects. 



Think of a fish that has a prehensile tail and is able to suspend 

 tself, monkeylike, by curling the end of it around the stems or 

 branches of aquatic plants! Its extraordinary method of reproduction 

 is no less remarkable than its peculiar structure. The male develops 

 a large pouclilike organ on the underside of the body. In the process 

 of reproduction the eggs are transferred from the female into the 

 specialized organ of the male, where they are incubated and the 

 young remain for some time after hatching.^ It seems that when 

 nature created the seahorse it was determined to do a good job and 

 concentrated all sorts of oddities in this little creature. Here is a 

 fish the head of which resembles that of a horse; with a hard-jointed 

 external skeleton resembling that of an insect; with a prehensile tail 

 like a monkey's; and with a pouch on its underside for carrying its 

 young after the fashion of a kangaroo, but the male instead of the 

 female acts as an incubator and carries the young. 



Notwithstanding the wide popidar and scientific iuterest that these 

 truly fascinating living things have attracted, it is remarkable, and 

 in a measure symptomatic of the state of taxonomy of fishes in general, 

 how much misapprehension exists in regard to the proper distinction 

 of the separate species, as the data presented here will amply 

 prove. To show the existing chaotic state in the systematics of 

 Hippocampus, the genus of seahorses, some of the results of my study 

 may be considered here briefly. 



This investigation was undertaken chiefly to evolve satisfactory 

 characters for separating the species found on the Atlantic and Pacific 

 coasts of North and South America and to establish definitely the 

 intraspecific ranges of variation. It was found desirable to include 

 also the species from the coasts of Europe, since they are very closely 

 related to the common American species, and there was some question 

 as to whether they are really distinct. It has also been necessary to 

 establish five new species, which were briefly described in a preliminary 

 paper,^ and one new subspecies, described herein. Furthermore, five 

 more or less recent names proposed for seahorses from American 

 waters had to be reduced to synonymy. The appropriateness of the 

 synonymic reduction of one or tv/o of these names may be open to 

 question until their types are reexamined, but their authors certainly 

 did not prove the distinctness of the supposedly new species. 



A suggestive case of the existing errors in the systematics of Hip- 

 pocampus may be cited here. According to the generally accepted 



' For a review of the known facts in the biology of tlie seahorse, see Gill, Proc. U. S. Nat. Mus., vol. 28, 

 pp. 805-814, 1905; and Kauther, Syngnathiden des Golfes von Neapel, 1925. 

 « Journ. Wa.shington Acad. Sci., vol. 23, pp. 560-563, 1933. 



