84 NEW GYEODACTYLOID TREilATODES FROM AUSTnALIAN FISHES, 



investigated, will be found to be exceedingly well represented in our waters, the 

 existence of such an array of monotypic genera being scarcely likely. 



An interesting result of the work is the ^establishment of a totally distinct 

 and sharply defined subfamily, Lepidotreminae, to include certain genera found 

 on fishes in the freshwater rivers of Central Queensland (inland drainage system) 

 as well as closely allied genera ocoumng on oui' mai-ine fishes. 



Though the rivers of Central Queensland now belong to an extensive inland 

 drainage system, they formerly had a commmueation with the ocean. Mr. A. 

 McCulloeh, Zoologist to the Australian Museum, Sydney, with whom we dis- 

 cussed this matter, drew our attention to the fact that all Australian freshwater 

 fishes belong to families which are essentially marine, e.g. most of them belong 

 to the pei'ch family {Serranidae), others to the Atherinidae, MugUidae, etc., while 

 the catfishes belong to the Plotosidae {See Tate Regan, Proc. Zool. Soc. Lond., 2, 

 1909, p. 770, footnote). 



Of course there is a large anadromous fish population, e.g. species of 

 Galaxias, Anguilla, gobies, mullets, etc., but we have not j'et systematically 

 searched members of these groups. 



We might point out tliat almost the whole of the freshwater material dealt 

 with in this paper came from the Thomson River at Longi'each, Central Queens- 

 land, — a tributary of Cooper's Creek; and most of the remainder from the 

 Upper Burnett River which flows into the Pacific. Both collections were made 

 by Miss M. J. Bancroft, B.Sc, whilst engaged in an attempt to ascertain the 

 cause of widespread mortality of fish in Queensland waters (Johnston and 

 Bancroft, 1921). 



The types of all the new species described in tliis paper have been deposited 

 in the Australian Museum, Sydney. 



In the present paper there are proposed one new superfamily (Gyrodacty- 

 loidea) ; one new family {Protogyrodactylidae) ; five new subfamilies' (Proto- 

 gyrodactylinae, Lepidotreminae, Merizocotylinae, Dionchinae, Protomicrocoty- 

 linae) ; and seventeen new genera or subgenera. Of the latter, five are based 

 on .species described by G. A. MaeCallum from North American fish, while the 

 other twelve are founded on new species described in this paper as infesting 

 Queensland fish. 



These twelve, with their type species, are as follows: — Protogyrodactylus 

 (P. quadratus) ; Trivitellina {T. subrotunda) ; Ancliylo discus {A. tandani) ; 

 Haliotrema {H. australe) ; Daitreosoma {D. constrietum) ; Empleurosom-a {E. 

 pyriforme) ; Lepidotnema (L. therapon) ; Flabellodiscus (F. simplex) ; Lepidotes 

 (L. fluviatilis) ; Empleuro discus {E. angusius) ; Acleotrema [A. girellae) ; Lamel- 

 lodiscus {L. typicus). 



The five new genera proposed for species already known are Diplectano- 

 trema — for Diplectanum pleurovitellum, MacC; Emprutliotrema — for Acanthocotyle 

 raiiae MacC; Cathmri-otrema — ^for Monocotyle selachii MaeC; Dionchotrema — for 

 Acanthodiscus remorae MacC. ; Protomicrocotyle — for Acantho discus mirabilis 

 MacC. No less than thirty-six genera are herein listed under the new super- 

 family. 



In addition to the seventeen Australian species described as new, fresh 

 names have been proposed for two others described by MaeCallum from North 

 American Elasmobranehs, and belonging to the genera AmpMbdella and Mono- 

 cotyle. 



The following table indicates the scheme of classification proposed in the 

 present paper: 



