PALUDINA SUBPURPUREA. 



SPECIFIC CHARACTER. 



Penultimate longer in proportion than the other yoIu- 

 tions. 



SYNONYM. 



P. SUBPURPUREA. Dissemiiiator of Useful Knowledge. 

 vol. ii, p. 245. 



DESCRIPTION. 



Shell subglobular oval, not remarkably thickened : spirt 

 longer than the aperture, entire at tip : ichorls five, slight- 

 ly wrinkled across, rounded but not very convex ; penul- 

 timate volution somewhat elongated : suture impressed : 

 aperture ovate-orbicular, less than half the length of the 

 shell : labium with calcareous deposite : animal very pale 

 bluish, with minute yellow points, particularly on the ros- 

 trum, tentacula and prominent respiratory tube, which is 

 as long as the tentacula : eyes on the exterior side of the 

 tentacula, near the middle of their length : the anterior 

 portion of the foot is very short. 



OBSERVATIONS. 



This species was first found by Mr. Lesueur and Dr. 

 Troost, in Fox river, of the Wabash. In the young state 

 the figure is subglobosc, and the aperture, although it hard- 

 ly differs in form, from that of the adult, is yet longer than 



