58 ILLINOIS BIOLOGICAL MONOGRAPHS [338 



Diesing 1834 from the intestine of a fish (Leuciscus) in Europe, a form 

 which Stafford (1896) and Kofoid (1899) suspect of being identical with 

 A. co-nchicola. The species A. macdonaldi was placed in this genus by 

 Montieelli (1892) and removed to Lophotaspis by Looss (1902). Linton 

 (1905) described A. ringens from the intestine of Micropognon undula- 

 tus and Trachinotus carolimis at Beaufort, North Carolina. MacCallum 

 and MacCallum (1913) gave a more complete description of A. ringens 

 and described A. kemostoma n. sp., both from the intestine of Trachinotus 

 carolinus. 



II. Cotylaspis Leidy 1857. Type species, C. insignis Leidy. 

 Oval adhesive disc, three rows of alveoli, marginal organs present, 



mouth subterminal, no oral sucker, one testis. 



This genvis contains the species C. insignis, C. lenoiri, and C. cokeri. 

 C. lenoiri was described by Poirier (1886) as a species of Aspidogaster. 

 Montieelli (1892) created a new genus Platyaspis to contain Poirier 's 

 species, evidently overlooking the similarity between it and the form re- 

 ported by Leidy. He declined to accept the genus Cotylaspis, suggesting 

 that C. insignis was a species of Aspidogaster. Braun (1879-1893) as- 

 cribed the species to Aspidogaster. Kofoid (1899) established the val- 

 idity of Leidy 's genus but contended that the genus Platyaspis should be 

 retained for Poirier 's species. Nickerson (1902) argued that tlije differ- 

 ences between the African and American species are not of generic im- 

 portance and suppressed the genus Platyaspis, making Aspidogaster 

 lenoiri Poirier and Platyaspis lenoiri (Poir. 1886) Montieelli 1892, syn- 

 onomous with Cotylaspis lenoiri Poir. Cotylaspis insignis occurs ectopara- 

 sitically in the mantle cavity of Unionidae in North America ; C. lenoiri 

 is from the intestine of Tetrathyra vaillanti of Africa; and C. cokeri is 

 from the intestine of Malacoclemys lesueurii of North America. 



III. Macraspis Olsson 1868. Type species, M. elegans Olsson. 



A single row of confluent acetabula in adhesive organ, marginal or- 

 gans present, mouth terminal, one testis. 



The single species is parasitic in the gall bladder of Chimaera mon- 

 strosa, a fish from the coast of Europe. 



IV. Stiehocotyle Cunningham 1884. Type species, S. nephropis 

 Cunningham. 



A single row of more or less distinct acetabula, marginal organs lack- 

 ing, mouth subterminal, oral sucker absent, two testes. 



Cunningham's original description was of the larva and Montieelli 

 (1892) declined to recognize its generic importance, thinking it might 

 be a form of Macraspis. Odhner (1898) by discovering the adult and 

 tracing the life history, established the genus. Adults live in the bile 

 ducts of the liver of rays ; larvae occur encysted in the wall of the intes- 



