BES MOINES ACADEMY OF SCIENCE. 



r * Mar^aritana eoiiiplanata, Barnes. 



(Am. Jour. Sol. and Arts, 1st Series Vol. VI, PL XIII, Fig*. 17a, 17b.) 

 Western New 'York to Alabama; to Kansas; north to Lake Wkinepeg. It is 

 usually an abundant species in the north and west central states and especially 

 so IB those contiguous to the Mississippi. This species is very readily recog- 

 ui/cd by its flattened aaid somewhat circular outline and alate dorsum. It is our 

 .largest 



*Margaritaiiii confragosa, Say, 



(Descriptions of tire Shells of North America, PI. XXI. As Alatmodonta, canfragosa.) 



\Vestern Indiana k> Iowa,. Specimens liave also been received from Trinity 



river, Texas, but fro-in no intermediate stations. It appears to be very abund- 



ant near Springfield, Illinois, but is elsewhere somewhat rare and local. Des- 



cribed from Fox river, a tributary to the Wabash. 



f Margaritaiia euiTeyana, Lea. 



(Trans. Am. Phil. Soc., 2d Series, Vol. VIII, PI. XIX, Fig-. 41.) 

 Stone river, Tennessee, and Tennessee river in North Alabama. These are 

 the only localities yet reported. Groups with and probably a synonym of 

 Marg. fabula, Lea. 



f Jttargaritana th'hiseens, Say. 



(Descriptions of the Shells of North America, PL XXI, as Unio dehiscem.) 

 This species, which Is rare aixl local, was described from the Ohio river from 

 which it ranges to Illinois. Specimens have been received from the Holston 

 river, in East Tennessee, taken by Mrs. Geo, Andrews. 



*XL argaritima deltoidea, Lea. 



<Trans. Am. Phil. Soc., Vol. VI, PL XIII, Fig. 38.) 



This form has the saire geographic distribution as Marg. calceola with which 

 it is certainly synonymous. It is very abundant at numerous localities in Illi- 

 nois and Indiana. 



rMarsaritanafalmla, Lea. 



(Trans. Am. Phil. Soc., Vol. VI, PL XIII, Fig. 39.) 



Described from the Cumberland river, Tennessee, See under Marg* currey- 

 ana* 



CATALOGUE ?* 



