202 s. GOTO. 



parasita." Altliougli in tliose diagnoses the only point of clifTerenco of some generic 

 importance observed by the author seems to have been the pediculate condition of 

 the posterior suckers of the one in contradistinction to those of the other, yet most 

 of tlie species known to Diesing and placed by him respectively in the two genera 

 are precisely those which, though I have not been able to study them personally, 

 still judging from the descriptions of others, I should bring just under those two 

 genera in which they are respectively included by him. Thus there can be no doubt 

 on the one hand that 0. scombri (KuhnJ, one of the two species described by 

 Diesing, is to be included in this genus as I have characterised it below. On the 

 other hand, DicUdojJiora Merhnir/i (KalotJ is, to judge from its (incomplete) descrip- 

 tions given by Dieckhoff, '^ in all probability to be included under Dididojihoia 

 as defined below, while as to 77. jxdiiuita fLeuck.J there can be no doubt, from the 

 general form of its body, of its belonging to the same genus. As to Octocoti/Ie htn~ 

 ccolata (F. S. LeiicJc.J there is no doubt from its descriptions given by Di eckhoff ^J 

 that it is to be brought under another genus, the most salient point of difference 

 being the presence of a dorsal vagina. I have, however, adopted Diesing' s 

 nomenclature, as he seems to be the first who has recognised the difference of the 

 two genera under question. P. J. v. Bene den and Hesse also have noticed this 

 difference and included them under two genera, Octocottjlc and Pterocoti/le ; the latter 

 being co-extensive with our Dielidoßhora, as may be seen from the following diag- 

 nosis given by the authors : " Huit ventouses portées sur de longs pédoncules 

 unis à la base terminent le corps en arrière. Le ver est régulièrement efiilé en 

 avant, large vers le milieu et rt-trcci vers l'origine des ventouses. La bouche est 

 flanquée de deux ventouses et une couronne de crochets entoure l'orifice des organes 

 sexuels." Like Diesing these authors regarded the unimportant pedicels of the 

 posterior suckers as of generic value ; but their idea is capable of a surer foundation, 

 as may be seen from the diagnoses of the two genera given below. 



The name Octostoitia was proposed by Kuhn in 1829; but like most writers 



singulum qnadri valve, valvulis semicirciilaribus, membranaceis, limljo corneo cinctis, asser- 



culatis, ia caivliue transverso moljilibus. Androgyna ; apertura genitalis mascula feminea 



autrorsum sita, uncinulorum corona simplici cincta. Porus excretorius Tractus in- 

 testinalis bicrnris, coeciis. — Ovi^iara, ovulis utraque extremitate appendice filiforme ci-asso. — 

 Piscinm marinorum ectoparasita." The penis is evidently mistaken for tlie female genital 

 opening. 



1). Dieckhoff— ?. c. ix 205. 



2). Dieckhoff— ;. c. p. 255. 



