o£ the Scientific Bureau of Manila this parasite caused deaths of the hosts. 



It is possible , consequently, that A. manilensis was not discovered in natural p. 232 



conditions. Even though they are related in the wide sense of the word, all three 



of the indicated families of fishes are, nevertheless, somewhat distant from 



each other. 



Ancyrocephalus mogurndae was encountered in the beginning 

 on two fresh water fishes - - Mogurnda obscura (Temm. & Schleg. ) and 

 Chaenogobius annularius urotaenia (Hilgend. ) and only at the latest time 

 was indicated from the Amur basin on the gills of Siniperca chuatei (Bar. ) 

 by Acknnerov (1952) and by Gussew (1955). Besides, Ackm.erov indicated 

 that this species of Ancyrocephalus was described by him on Erythroculter 

 oxycephalus (Bleck. ), "apparently accidentally'' which is undoubtedly a 

 mistake in labeling. The finding of this species on Siniperca does not 

 arouse any doubts in us after personal study of the material. Thus we 

 must recognize as correct that A. mogurndae is encountered in three 

 families of Perciformes, Electridae , Gobiidae and Serranidae. The first 

 two are closely related to each other, whereas Serranidae are quite re- 

 moved from them. It is possible that the conditions of existence in the 

 fresh water help the transfer of A. mogurndae from the Bichok (Gobiidae 

 Cottus sp. , nobis ) to Serranidae. One cannot fail to note one additional 

 interesting circumstance and that is that in the Amur River, A. mogurndae 

 is not encountered on Percottus glehni although this species is related to 

 Eleotridae and it would seem would have all the chances to be infected, 

 at any rate sooner than Sineperca. 



Ancylodiscoides various is known from two very close species 



of Siluridae^ and is indicated by Ackmerov from Liocassis ussuriensis (Dyb. ) 

 (Bagridae). As Gussew quite correctly points out (Gussew, 1955) , the 

 latter is undoubtedly erroneous. 



En cotyllabe spari is encountered in Sparidae, Serranidae, and 

 Pomadsyidae, i.e., on perciformids related to one superfamily, Percoidae, 

 and undoubtedly related to each other. 



In this same fashion Thaumatocotyle dasybatis is encountered 

 in two genera of Trigonidae and on Rajidae; both families are undoubtedly 

 related (Suvorov, 1948). 



Heterocotyle minima is indicated on skates of two genera of 

 Trigonidae and besides that on the shark- -Squalus acanthias L. (Squalidae). 

 There are no details whatsoever on the subject of the finding of H. minima 

 on the latter species in the work of Price (Price, 1938a) in which this host 

 is first cited. Thus, for the time being H. minima must be considered as 

 being encountered only on relatively distant hosts, it is true apparently 

 basically on skates and only accidentally on the shark. 



257 



