184 KOFOID. [Vol. II. 



genera, as described, are the presence or absence of eyes, the 

 number of alveoli in the ventral sucker (29 in Cotylaspis and 

 25 in Platyaspis), and the ectoparasitic habit of the one and 

 the endoparasitic habit of the other. Here, again, the absence 

 of eyes in Platyaspis is inferred from Poirer's silence upon the 

 subject. The endoparasitic habit of Platyaspis may also be 

 questioned, for turtles are wont to feed upon molluscs, and 

 molluscan parasites have been found in the intestines of mol- 

 lusc-eating vertebrates. For example, Stafford ('96) suggests 

 on the basis of the variation in form observed by him in Aspido- 

 gaster conchicola that A.lintacoides Diesing, from the intestines 

 of European fishes, is only an A. conchicola which had been 

 taken into the digestive tract of the fish with its food. Simi- 

 larly I have myself found in the intestine of Cyprinus carpio and 

 Moxostoma inacrolepidotiim specimens of Aspidogastcj^ which 

 externally do not differ from A. cojic/iicola. Furthermore, in 

 one instance they were found with a mass of the glochidia of 

 Anodonta — a coincidence which suggests their source. How- 

 ever, the data at hand do not justify, to my mind, the reduction 

 of Platyaspis to a synonym of Cotylaspis. Monticelli's genus 

 should, for the present at least, be retained for the reception of 

 Poirer's species. Should future investigation reduce the now 

 considerable differences which separate the two forms, and 

 render advisable the assignment of the two species, C. insignis 

 and B. lenoiri, to the same genus, then Leidy's Cotylaspis will 

 take precedence of Monticelli's Platyaspis. 



I give below the synonymy of Cotylaspis insignis. 



Cotylaspis iiisignis Leidy (1857). 



Cotylaspis insignis Leidy ('57). 



Cotylaspis insignis Leidy ('58). 



Cotylaspis insignis Diesing ('59). 



Cotylaspis insignis Taschenberg ('79). 



Cotylaspis insignis Hoyle ('88). 



Aspidogaster conchicola (in part) Monticelli ('92). 



Aspidogaster insignis Braun ('89-'93). 



Platyaspis anodontae Osborn ('98). 



In this note the aim has been to show that Aspidogaster 

 conchicola occurs in this country; that Cotylaspis insignis he'idy 



