76 AN ANNOTATED CATALOGUE 



Anodonta grandis Say. Abundant everywhere espe- 

 cially in the ponds and bayous adjacent to the water- 

 courses. This species though never figured, is well known 

 to collectors generally. 



Anodonta imbecilis Say. Common in many localities of 

 eastern Iowa. In August, 1885, this species was found 

 abundantly in the Minnesota river at Ft. Snelling. 



Anodonta ovata Lea. Specimens referred to this spe- 

 cies are abundant in Okoboji and Spirit lakes, Dickinson 

 county. 



Anodonta plana Lea. Not uncommon in the Des Moines 

 river and elsewhere. This is another of the grandis group ; 

 and it is extremely doubtful whether this form should be 

 specifically separated from the type of the group. 



Anodonta suhorbiculata Say. Abundant in numerous 

 localities in eastern Iowa. 



Anodonta wardiana Lea. Common in the Beaver creek 

 and Des Moines river near Des Moines. 



Margaritana calceola Lea. The distribution of this spe- 

 cies is more general east of the Mississippi river, but has 

 been collected in various localities in eastern Iowa. M. 

 dtltoidea Lea is regarded as synonymous with this and 

 hence no mention is made of that form which has been re- 

 ported from certain localities in the state. 



Margaritana complanata Barnes. Abundant : Rock 

 river, northwestern Iowa, Shell Rock river in Floyd coun- 

 ty, Mississippi, Iowa, Des Moines and Missouri rivers. 

 This is the largest of the genus occurring in the state ; it 

 is usually symphynote, but specimens from the Shell Rock 

 and other localities do not possess the alate dorsum ; the 

 latter variety is generally much heavier than the former. 



Margaritana confragosa Say. This species does not ap- 

 pear to be common in any Iowa localities. It is found as 

 far north as Fort Snelling, where it has been collected in 



