OF CONCHOLOGY. 157 



24. Dsedalochila auriculata, Say. 



Plate 11, figures 13, 14. 



Spire low, conical ; whorls 5, ribbed-striate above and below, 

 the periphery slightly angulate ; last whorl suddenly deflected 

 to the aperture, and very strongly scrobiculate behind the middle 

 of the right margin, and also at the base ; aperture oblique, 

 auriform, the parietal tooth large, irregular, projecting inwards 

 and upwards, the right margin with a perpendicular lamellar 

 tooth, and the base twisted into a large oblique tooth ; base 

 showing 1| whorls, the umbilical region bounded by a carina. 



Diam. 13, height 7*5 mill. 



St. Augustine, Florida. 



Larger than the other species, and distinguished by the ribs 

 on the base. 



25. Dsedalochila uvulifera, Shuttleworth. 



Plate 11, figures 15, 16. 



Spire depressed conical; whorls 5, Vith close ribs extending 

 entirely across the base ; periphery subangulate, lower surface 

 convex ; last whorl deflected at the aperture and scrobiculate ; 

 aperture oblique, much contracted by teeth, with the lip very 

 much expanded, parietal tooth quadrately linguiform, extending 

 into the aperture, the upper lip tooth situated far within the 

 aperture, the basal lip tooth an oblique plication ; umbilical re- 

 gion subcarinate. Horn color. 



Diam. 12, alt. 7 mill. 



Florida ; Corpus Christi, Texas. 



Smaller, with difi"erently formed aperture from D. auriculata. 



POLYGYRA, Say. 



This is a tropical genus, containing many flat, wheel-shaped 

 species which inhabit the shores of the Gulf of Mexico, the West 

 Indies and Mexico. The southern limit of the group extends to 

 the vast regions of the empire of Brazil, whence come the curious 

 P. heligmoidea and P. hel icy chide a. Unlike DcedalocJdla^ the 



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