329] NORTH AMERICAN ASPIDOGASTRIDAE—STUSKARD 49 



COTYLASPIS INSIGNIS Leidy 1856 

 [Figure 56] 



The material of this species consists of specimens from Anodonta 

 imbecilis, A. corpulenta, Lampsilis gracilis, and Vnio pustulosis from 

 Havana, Illinois, and others from Anodonta ferrus and A. ovata from 

 Reed's Lake near Grand Rapids, Michigan. The material proved to 

 belong to the same species and was identical with C. insignis Leidy. 



Leidy first discovered the parasite in the Unionidae of the Schuyl- 

 kill River and founded the genus to receive the new species. His generic 

 and specific diagnosis (1858) follows: "Body curved infundibuliform, 

 anteriorly cylindro-conical, posteriorly expanding into a subcircular or 

 oval ventral disc with numerous acetabula arranged iu a triple series. 

 Mouth infero-tei'minal, with prominent upper lip, and protractile into 

 a cup or disc like acetabulum. Intestinal apparatus as in Aspidogaster, 

 eyes two, distinct, black, situated on either side of the head. Generative 

 apertures inferior between the head and ventral disc." 



According to the same author, C. insignis, the type species is: 

 "Translucent white or pink white, upper lip snout like, conical, ventral 

 disc crenate at the margin : acetabula twenty-nine, oblong quadrate, the 

 outer rows continuous in front and behind forming a circle. Length 

 from one-half to one line ; ventral disc from one-fourth to one-half line 

 in diameter. Adheres to the outer surface of the renal organ and 

 upper margin of the foot, within the cleft of the upper branchial cavity 

 of Anodonta fluviatilis and A. lacustris." 



Forbes (1896) reported this parasite in the river clams at Havana, 

 Illinois. Osborn (1898) described the species from Lake Chautauqua, 

 New York, as Platyaspis anadontac. Kofoid (1899) corrected this 

 error, demonstrating that Leidy 's genus is entitled to recognition, and 

 establishing the specific identity of Platyaspis anadontac Osborn with 

 C. insignvi Leidy. Kelly (1899) reporting on the examination of over 

 sixteen hundred individuals of forty-four species of Unionidae found the 

 parasitt' in twenty-four different species of molluscs and in eighteen per 

 cent of the individuals examined. 



Osborn (1904) gives a review of the literature, an account of the 

 distribution, habits, external and internal anatomy of the mature worm, 

 and a description of a very young individual. The young specimen 

 described has a simple ventral sucker, no eye spots, no marginal organs, 

 two entirely distinct excretory systems, and wholly separate pores. This 

 condition of the excretory system is compared with the condition in 

 redia and eercaria and according to Osborn favors the idea suggested 

 by Leuckart that the Aspidogastridae are sexually mature redia. 



