STUDIES ON THE ECTOPAKASITIC TKEMATODES OF JAPAN. 201 



Habitat — Gill of Anthits Schlegelii (Jap. Akasagi), 

 Locality — Misaki. 

 Date— December 1889. 



in. OcTOCOTYLE, Diesing. 



This and the following genus Diolidojihom have been combined by most 

 writers under the name of Octobothrium. The latter name is due to F . S . 

 Leuekart" whose original diagnosis runs: "Corpus elongato, depresso, piano ; 

 apertura oris antica, infera, simplice ; in utroque partis corporis posticae latere 

 acetabula suctoria quator." He, however, included in it at least two groups of 

 forms which are, in my opinion, to be separated from each other and placed 

 in distinct genera. So far as I have been able to make out with a somewhat 

 scanty access to the literature of the subject, especially the older, Diesing is the 

 first writer who has made this distinction and erected two genera, which respectively 

 include those forms which are, in my opinion, to be brought under at least two 

 distinct genera. One of these has been named by him Octocotyle, the diagnosis 

 of which he gives as follows^) : " Corpus elongatum depressum. Caput corpore con- 

 tinuum. Os terminale. Acetabula in postico corporis margine unciuis duobus sub- 

 basilaribus interjectis utriuque quator, promiuula orbicularia inermia ( ? ) et duo 

 parellela infra os sita. Apertura genitalis feminea elliptica uneinulorum corona 



simpliei cincta. Penis Porus excretorius Piscium marinorum 



eetoparasita." The other of his genera is Dicl'ulopliora, the original diagnosis ') of 

 which ran : " Corpus subovale v. sublanceolatum depressum. Caput corpore con- 

 tinuum. Os subterminale. Acetabula in margine caudali oeto, solitaria, valvulis 

 4 membranaceis asserculatis, in cardine transverso mobilibus, louge pedicellatis. 

 Apertura genitalis Porus excretorius Piscium marinorum ecto- 



1). E. S. Leuckarfc — Versuoli einer naturgemiissen Eintheilung der Helminthem nebst 

 dem Eatwurf einer Verwandtschafts- und Stufenfolge der Thiere iiberhaupt. Heidelberg, 

 1S27. I make tbe above quotation on the authority of Braun (Wiiraier, p. 534), 



2). Diesing— Systema helminthum, vol. I, 1850. pp. 417 & 421. 



3). This was slightly improved in his " Revision der Myzhelminthen '' (p. 383) as follows : 

 " Corpus subovale v. sublanceolatum depressum. Caput coUo continuum, subtus acetabulis 

 duobus juxtapositis. Os subtermin-ale. Pleotana ooto pedicellata in postico corporis margine. 



