NO. 2194. NORTH AMERICAN PARASITIC COPEPODS— WILSON. 19 



site's body. Jungersen (1911, p. 1) found the external portion of 

 the body of the new copepod which he described completely coa - 

 ered with a gyninoblastic hydroid, so that "the parasite at first, 

 sight appears made up of a stem and a large number of branchlets,'" 

 the latter being the hydroids. 



Kellicott (1880, p. 66), in speaking of the adult Lenvicd cruchiio. 

 said that " the chitinous exterior, together with the external load of 

 confervae and infusorial life which they usually bear, render then\ 

 too opaque for satisfactory examination." 



Cunnington (1914, p. 827), in his remarks upon Lernaea haplo- 

 cephala^ a new species from the ganoid fish, Polypterus^ taken in 

 Lake Tanganyika and the White Nile in Africa, said: '" \'orticellids 

 infest many of these Lernaeids from the Nile to such a degree as to 

 render diflieult the study of their anatomy. Among a considerable 

 number of specimens taken on a Polypterus senegalis almost all are 

 infested, some of them as markedly as the one photographed (fig. 7). 

 The region where the vorticellids are most thickly attached is about 

 the junction of the thin anterior third of the body with the more 

 dilated posterior portion. It seems highly probable that the manner 

 in which these parasitic copepods can be so densely encrusted by such 

 organisms is directly related to the peculiar fact that after fixation 

 to their host they appear no longer to undergo ecdysis." 



Jungersen also mentioned several other examples of triple asso- 

 ciation between a hydroid, a parasitic copepod, and a fish. He him- 

 self had seen Ohelia geniculata "flourishing on a Lernaea'^ hran- 

 chialis attached in the gills of the common cod; a similar case is 

 mentioned by Saemundsson" (p. 28). 



Alexander Agassiz (1865, p. 87) found the hydroid Eucope 

 parasitica "on a species of Pennella parasitic on Oi'ihagonscufi 

 mola.^^ Later the same hydroid was taken by Leidy (1889, p. 165) on 

 another Lernaean, ^^ Lerneonema^ procera^^'^ parasitic on fiJo-^U(^)>'^ 

 littoralis." 



Many of the specimens of Lernaeenicus longiventns and L. radi- 

 atus in the United States National Museum collection are well cov- 

 ered with hydroids and algae. 



Ciliate infusoria are also often attached to Pennella and Lernaeeni- 

 cus, sometimes in company with algae, sometimes alone. The 

 Lernaeans which fasten to the gills or on the inside of the gill 

 chamber for the most part escape these Epizoans, but specimens of 

 Lernaeolophvs and Haemohaphes are occasionally obtiiined with 

 algae fastened to the posterior processes or the abdomen. Indeed 

 Peniculus is the only genus upon which none of thest' Forms have 

 been recorded, and this is probably an omission. 



1 A synonym of Lernaeocera hranchialis. 

 * A synonym of Lemaeenicus procerus. 



