﻿32 MICWOMYA 



I.cng-th (female) 39, heig-ht 24, diam. 20 mm. 



Cumberland and Tennessee Rivers. 



Type locality, Tennessee. 

 Unio deinatiis Reevij, Conch. Icon., XVI, 1864, pi. xv, fig. 6r. 



— Anthony, Am. Jl. Conch., I, 1865, p. 156, pi. xii, fig. 2. 

 Mar gar on (Unio) deinatus Lea, Syn., 1870, p. 42. 

 Truncilla deviata Simpson, Syn., 1900, p. 524. 



Probably distinct from T. Aoretitina, thoug+i it may be but 

 a variety of it. Reeve figured it in the Conchologia Iconica, 

 but his specimen was not characteristic and he credited it to 

 Anthony's manuscript in Museum Cuming. The next year, 

 1865, Anthony described it in the American Journal of Conch- 

 ology and gave a characteristic figure of a female shell. The 

 only male shell I have seen is in the Lea collection, 27 milli- 

 meters long, 19 high, and 13 in diameter, is no doubt young 

 and has the beaks much eroded. The female shells are more 

 -elongated than those of iiorentina, have much fuller, higher 

 beaks and the marsupial swelling is rather more produced. It 

 has been found at Hardy, Arkansas, by Mr. J. H. Ferriss. 



Unfigured and indeterminate species. 



Truncilla (Unio) perplexus Rafinesque. 

 Truncilla granulatns Rafinesque. 

 .Unio {Truncilla,) metaplata Rafinesque. 



All of these in Continuation of Monog., 183 1, p. 4. 



Genus MICROMYA (Agassiz, 1852) Simpson. 



Micromya Agassiz, Arch, fiir Nat., 1852, p. 57. — Ortmann, 



Ann. Car. Mus., VIII, 19 12, p. t^t,/. 



Shell subtriangular oval, solid, dark, feebly rayed with un- 

 dulating lines ; beak sculpture almost wanting, consisting of a 

 few feeble, doubly-looped ridges ; hinge teeth heavy, laterals 

 club-shaped and truncated posteriorly ; post-basal swelling of 

 the female distinct and often rather abrupt, sometimes some- 

 what irregularly radially ridged, the shell of this part being 

 •quite thin. 



