42 TIIK NAUTILUS. 



radiating from the umbilicus and ending at the carina. Color like 

 the type, generally yellow or yellowish-white with very faint or no 

 brown patches on under surface. Whorls about 0-|. 



Greater diam. 19, lesser 17, alt. 9 mm. 



Greater diam. 19, lesser 1G^, alt. 9 mm. 



The very heavy ribs ending on the ca/rina will serve at once to 

 distinguish this from any of the other numerous varieties of alternata. 

 There is a wide variation in the number of ribs on the body whorl 

 as the following figures will show : 



Diam. 19 mm., 24 ribs. 



Diam. 19 mm., 38 ribs. 



Diam. 17^ mm., 32 ribs. 



So far reported from " East Tennessee " (Lewis) and Cades Cove, 

 Blount Co., Tenn. (Ferriss & Clapp). 



Another variety of alternata is found near Knoxville, Tenn. It 

 is a large, coarse shell with rounded body-whorl and scarcely a trace 

 of carination. Color dull brown with very faint darker markings, 

 ribs low but fairly strong, epidermis very heavy and wrinkled, the 

 wrinkles under a glass having a netted appearance like the venation 

 in the wings of insects. Whorls 5^. 



Greater diam. 23i, lesser 20, alt. 12^ mm. 



NEW SOUTHERN UNIOS. 



BY BERLIN II. WRIGHT. 



U. polymorphus, sp. nov. 



Shell smooth, uniformly but moderately solid, red or dark red, very 

 inecmilateral, oval, oblong or subquadrate, rayless or with rays ; pos- 

 terior area smooth, wrinkled or subplicate ; umbos flattened or in- 

 flated, umbonal ridge sharp and area abrupt, or ridge depressed and 

 area flattened ; base nearly straight or emarginate, dorsum arched, 

 abruptly rounded in front and bluntly pointed behind; beaks not 

 prominent ; teeth solid in proportion to shell, laterals nearly straight 

 or remarkably curved, prominent and well separated, double in the 

 left and single in the right valve, cardinals quite oblique, usually 

 disposed to be double in both valves and covered with shallow serra- 

 tions ; dorsal cicatrices in a row immediately under the posterior car- 

 dinal or under the dorsal plate, anterior cicatrices quite remote, very 



