THE NAUTILUS. 



VOL. XIX. 



JULY, 19O5. 



No. 3. 



POLYGYRA DECEPTA N. SP. 



BY GEORGE H. CLAPP. 



While collecting at Blount Springs, Ala., in July, 1904, Mr. 

 Herbert N. Smith gathered a good series of shells which, at first 

 glance, appeared to be Polygyra hirsuta, but careful examination 

 showed two species, a small form of typical hirsuta, gr. diain. 7, 

 lesser 6^, alt. 4^ mm., and the above-named new species, in the pro- 

 portion of about 1 of the former to 7 of the latter. 



P. decepta n. sp. 



P. hirsuta Say. 



By comparison with hirsuta the following differences will be 

 noted : Lip broader and more rounded at the top so that when the 

 shell is viewed from below, the body-whorl joins it in a regular curve 

 instead of forming an obtuse angle ; parietal tooth hooked at the 

 outer end and curving into the aperture, the lip being deeply re- 

 cessed around it ; lip-notch narrow and sinuous with a well raised 

 margin which projects above the level of the parietal tooth ; width 



