XORTH AMERICAX POLVSTOMlDAESTrXKARD 



POLYSTOMIDAE 



HISTORICAL REVIEW OF THE FAMILY 



In 1758 Roesel von Rosenhof described and figured a "leeeir' from 

 tlie urinary bladder of the frog. Tliis is regarded as identical with the 

 well known European parasite of the urinary bladder of the frog, 

 described by Frohlich (1791) as Linguatuln integer rimum. M. Braun 

 (1792) described Planai-ia uncinulata from the urinary bladder of the 

 green water-frog and his description is so specific tliat there can be no 

 doubt that he had the same form described by Frohlich the previous 

 year. Zeder (1800) founded the genus Polystoma to contain the three 

 species, Linguatula intcgerrimum Prohlicli which he rechristened Pohj- 

 stoma ranac, P. serratum, and P. pinguicola. According to Stiles and 

 Hassall (1908) the type was clearly intended to be P. ranae = Plaiiaria 

 uuciiivlata, and altho Braun had described the form correctly with the 

 suckers and hooks at the posterior end of the body, Zeder erroneously 

 stated in liis characterization of the geuus that the suckers were at the 

 anterior end. P. serratum had been designated by Frohlich (1789) as 

 type of the genus Linguatula and P. pinguicola had been designated by 

 Treutler (1793) as type of the genus Ile.xathyridium. That Zeder was 

 in error in including these species in the genus Polystoma was demon- 

 strated by later studies. However Rudolphi (1809) retained them in the 

 genus Polystoma and listed three other species: P. taenoides Rud., P. 

 drnii<:iilatiim, Rud., and P. vcnarum (Treutler 1793) Zeder 1803. 

 Among these species, it is probable that Treutler's description was of an 

 artifact rather than a parasite, and tlie other two have been i-cmoved to 

 the Linguatulidae. 



Pohjstoma thijnii was described from the gills of Scomber fhynnus 

 by Delaroche (1811). Rudolphi (1819) renamed this species P. dupUca- 

 tum and added a new species P. occllatum from tlie tliroat of Emgs 

 europa. This species is regarded as identical witli that described by 

 Kuhl and Hassalt (1822) from the nasal cavity of Ilalirhrli/s atra. P. 

 logiginis was described by delle Chiaje (1823) from LoUgo vulgar i,<. 

 Blainville (1828) oriented the polystomes correctly and transferred P. 

 iniegerrimum, P. orellatum, and P. thgnii to a new genus Ile.xacotyle, 

 naming H. thynii as type. According to the rules of zoological nomen- 

 clature, however, the genus Polystoma must be retained. Kuhn (1829) 



