28 University of Michigan 



inannsen, '47, p. 436 (type, U. dilatata Raf.) ; Agassiz, '52, p. 45 (type, 

 U. recta Lam.). 



Cunicnia Swainson, '40, p. 378 (no type named) ; Herrmannsen, '47, 

 P- 335 (type, U. purpurascens Lam.). 



The type of Burynia has been designated by Herrmannsen 

 as U. dilatata Raf., a species congeneric with the type of Ellip- 

 tio. Thus, Blliptio and Eurynia are equivalent and have the 

 same date of pubhcation. Our preference given to Blliptio 

 is justified by Art. 28 of the Code and the recommendation 

 (c) as to page precedence. Agassiz's designation of recta as 

 the type of Burynia thus becomes invahd. 



Herrmannsen's type of Cunicida being congeneric with the 

 type of Blliptio, that genus also becomes a synonym of Blliptio. 



Eluptio crassidEns (Lamarck), 19 19 

 Type locality: Lake Erie (erroneous). 



Unto crassidcns var. b. Lamarck, '19, p. 71. 



Unio nigra Rafinesque, '20, p. 291, pi. 80, f. 1-4. 



Unio cuneatus Barnes, '23, p. 263. 



U. crassidens, var. b. Lam. =: U. cuneatus Bar., Lea, '34, p. 87 (type 

 •examined). 



U. niger Raf. == U. cuneatus Bar., Conrad, '34, p. 70. 



U. niger Raf. = U. crassidens var. b. Lam. = U. cuneatus Bar., 

 Ferussac, '35, p. 27; Conrad, 'z(>, P- 49, pl. 26. 



Unio crassidens Lam. Simpson, '14, p. 606. 



U. nigra Raf. = f/. crassidens Lam. (of Simpson), Vanatta, '15, p. 

 555 ("type" examined). 



Elliptio niger (Raf.), Utterback, '16, p. 88; Ortmann, '18, p. 555. 



Unio crassidens Lam. = U. nigra Raf., Walker, 'i8c, p. 174 (if iden- 

 tifiable). 



"Lamarck proposed this species to include several long, solid 

 forms which we now know belonged to three species, still 

 another being included by him in the citation of a figure from 

 Lister. One of these species is now known, from examination 

 of his specimens, to be a plicate shell ; the others are smooth. 

 There is some difference of opinion as to whether he intended 

 to describe crassidens as plicate, but as he included two 



