resume is based on the earlier data of MacCallum (MacCallum, 1917). 

 Thus, even the given species actually is encountered only on one host. 



D. pollachii and D. minor are indicated as discovered on 

 Odontogadus nnerlangus (L. ), the first in addition on PoUachius pollachius 

 (L.. ) and the second on Micromesistius poutassou Risso, and the usual host 

 for both species is the second host. The data about the finding of D. 

 pollachii on Odontogadus belong mainly to the first half and middle of the 

 last century and are apparently based on a faulty determination of the 

 parasite. Indications to the presence of D. minor on Odontogadus are 

 found only in one work (Rees and Llewellyn, 1941) and as Sproston correctly 

 writes, "if the identifications of host and parasite are correct, this is one of the 

 exceptional departures from rigid host-specificity in the subfamily. " (Sproston, 

 1946, page 482). It is more probable that here takes place an error in determination. 



Finally ,the data about ftie finding of D. morrhuae on Odontogadus 

 merlangus (L. ) in addition to the usual host, Gadus morrhua (L, ),are based 

 on the inaccurate determination of the parasite and refer to another species p. 242 

 as Price correctly points out (Price, 1943a). 



From the seven species of Urocleidus pertaining to the given 

 group (this group of parasites under consideration, nobis) , U. mucronatus 

 Mizelle encountered on Helioperca incisor (C. and V. ), AUotis humilis 



_ 



There is reason to believe that this species is a synonym of U. ferox 

 Mueller, 1934 (Mizelle and Donahue, 1944). 



(Giz. ), Eupomotis gibbosus (L. ) and Lepomis macrochirus Raf. deserves 

 special nnention. All the enumerated species are very close to each other; 

 this is substantiated on the one hand by the fact that they have often been trans- 

 ferred from one genus into another (thus H. incisor was formerly referred to 

 the genus Pomotis and to Lepomis, AUotis humilis--to the genus Lepomis , etc. ), 

 and on the otner that these species hybridize. It is interesting that the 

 proximity of the enumerated hosts is substantiated by the finding of U. 

 mucronatus on the hybrids between H. incisor and E. gibbosus and between 

 A. humilis and E. gibbosus (Mizelle, 1936). 



Among eight species of Gyrodactylus related (to this group of 

 parasites under consideration, nobis) one must note two species-i-G. 

 groenlandicus Levinsen and G. gobioninum Gussew. The first of these 

 is described by Levinsen (Levinsen, 1881) from Myoxocephalus scorpius 

 (L. ) and then encountered by us in the Pacific Ocean near the shores of 

 Sakhalin and near the southern Kurile Islands on young Myoxocephalus 

 species, Blepsias cirrhosus Jord. and St. and Opisthocentrus zonope 



270 



