ON THE SPECIFIC IDENTITY OF COTYLASPIS 



INSIGNIS LEIDY AND PLATYASPIS 



ANODONTAE OSBORN. 



CHARLES A. KOFOID. 



Two species of trematodes belonging to the suborder Aspido- 

 cotylea and the family Aspidobothridae occur in this country as 

 parasites of fresh-water clams. The first of these is the not 

 uncommon Aspidogaster concJiicola, described by von Baer ('27). 

 This is an internal parasite infesting the pericardium, the liver, 

 and the renal organ of many Unionidae of Europe and America. 

 Its occurrence in this country was first reported by Leidy {'51, 

 ■57, and -58) in Unionidae from Pennsylvania. It has also been 

 found in great abundance in various species of Unio and Ano- 

 donta from the Illinois River, examined at the Illinois Biological 

 Station at Havana, during the last five years. On grounds 

 which will be discussed later, Monticelli ('9o) has raised the 

 question as to the specific identity of the form reported by 

 Leidy and the Aspidogaster conchicola of Europe. It seems prob- 

 able, however, that Leidy had a form agreeing, in so far as he 

 described it, with the European species as then known. My 

 examination of the specimens from the Illinois River leaves no 

 doubt in my mind that Aspidogaster conchicola, as further de- 

 scribed by Voeltzkow and Stafford, occurs abundantly in that 

 locality, and thus far no other species of this genus has been 

 observed there, although over one thousand clams have been 

 examined by Prof. H. M. Kelly and myself for these parasites! 

 Under these circumstances the inference seems to be warranted 

 that von Baer's Aspidogaster conchicola occurs in this country 

 also, and is the common species, and the only one of the genus 

 as yet found here. 



The other trematode of this family which is a parasite of the 

 Unionidae, is Cotylaspis insignis Leidy, and up to the present 

 time it has been reported only from the Unionidae of the United 



