REVIEW OF HIPPOCAMPUS — GINSBURG 515 



The next writer we have to consider is Rafinesque/^ whose account 

 is as follows: 



"XIX G. Hippocampus — Un ala dorsale, un ala anale, nessuna 

 caudale. — Oss. II curioso Syngnathus hippocampus compone questo 

 genere insieme col S. tetragorius in opposizione del quale lo chamero 

 H. heptagonus." 



Having established the genus Hippocampus, he substituted the name 

 H. heptagonus for iS'. hippocampus, and this species is the type of 

 his genus by tautonymy. The S. tetragonus he mentions is evidently 

 Gmelin's species, which is now regarded as a synonym of Syngnathoides 

 or Gastrotokeus biaculeatus (Bloch).^^ In regard to Rafinesque's 

 restriction of the specific nam^e hippocampus, two interpretations are 

 possible: (1) Having listed the Sicilian seahorses as H. heptagonus, 

 he restricted the specific name hippocampus for which it w^as a sub- 

 stitute to a Mediterranean species; or (2) like his predecessors he 

 regarded the seahorses proper, the fishes now generally placed in the 

 genus Hippocampus, as belonging to one species and did not in any 

 way restrict the use of the specific name hippocampus. Since Rafin- 

 esque does not give an adequate account of the species, this question 

 remains unanswered. To settle the problem of nomenclature, 

 however, this question need not be answered, since Leach a Httle later 

 more definitely restricted the specifixC name hippocampus to a Mediter- 

 ranean species. 



Another author whose work appeared in the same year as that of 

 Rafinesque and has a bearing on the nomenclature of the seahorses is 

 George Perry. ^'^ This work was neglected by subsequent writers, 

 although it is superior to som.e publications that appeared contem- 

 poraneously. An account of it is given by Gregory M. Mathews and 

 Tom Iredale,^^ who list four extant copies known to them. According 

 to them. Perry's Arcana was issued serially as a monthly periodical, 

 and the separate numbers were bound together in book form having a 

 common title page, dated 1811. The library of the United States 

 National Museum has an incomplete copy, which I examuied ; it has a 

 written copy, but not the original, of the title page. It consists of 

 colored plates and descriptive matter without any page or plate num- 

 bers, but the plates bear dates. 



Two places in Perry's Arcana are to be considered in connection with 

 the nomenclature of Hippocampus. The first is a plate dated May 1, 

 1810. The accompanying letter press is headed: "Genus — Syngna- 

 thus, or Hippocampus/5'2>6C2e.s — Foliatus." The heading is followed 

 by an account of a single species, which is apparently the same as the 



"* Caratteri di alcuni nuovi generi e nuove specie di animali e piante della Sicilia, p. 18. ISIO. 

 " See Weber and Beaufort, The fishes of the Indo-Australian Archipelago, vol. 4, p. 39, 1922. 

 '1 Arcana; or The museum of natural history . . . , 1810. I am indebted to Dr. George S. Myers and 

 Austin H. Clark for calling my attention to this publication. 

 2' Victorian Nat;, vol. 29, no. 1, 1912. 



