THE NAUTILUS. 113 



cruenta for unquestionable specific distinction. The form has not 

 been known, at least to American collectors, until very recently. 



The shell bears the name of my good friend Mr. Isaiah Greegor, 

 of Cuyahoga Falls, Ohio, an untiring collector and student of 

 shells. 



THE UNIO MUDDLE. 



BY BERLIN H. AVRIGHT. 



For the past fifteen years my father and myself have been making 

 a study of the family Unionidse and have ^brought together some- 

 thing like 700 species. Like many others we have often been greatly 

 perplexed to know where to place a form, being frequently reminded 

 of what a celebrated palaeontologist once wrote me regarding a 



certain gastropod. "It is but if it had lived a little 



longer it would have been " 



Several years ago we brought to New York the results of four 

 years hard collecting in South Florida, several bushels of Unios. 

 The perplexing part of the work was commenced, having in hand a 

 figure or description or both of almost every species of the family. 

 All of the shells belonging to the trossuliis group were placed upon 

 a large table. There was U. amygdalum Lea, lepidus Gould, modioli- 

 formis Lea, and trossuhis Lea. Then with the figures and descrip- 

 tions of these species before us, we selected a few perfectly typical 

 individuals of each species and undertook the task of dividing the 

 mass of material into four groups corresponding with the above- 

 named species. There were not less than 500 individuals, all cleaned 

 and taken alive. Many days were spent in this work. At the close 

 of the day we would congratulate ourselves that they were correctly 

 divided and the next day on reviewing the work make many 

 changes, until, at last, we gave up in despair and have never dared 

 to send many of them out — only the extreme forms being thus far 

 used. 



Then the work of dividing the others in the same manner was 

 undertaken. Typical specimens of various ages and differing sexes 

 of the following species were selected. U. Buckleyi Lea, Jayanus 

 Lea, Anthonyi Lea, Buddianus Lea, aheneus Lea, Blandingianus 

 Lea, coruscus Gould (comparison having been made with the type at 

 Albany), fuscatus Lea, JewetUi Lea, minor Lea, Monroensis Lea 



