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PROCEEDINGS OF THE NATIONAL MUSEUINI 



VOL. 83 



threads. On the umbilical wall the spiral threads become much intens- 

 ified. Aperture broadly ovate. Peristome double, the outer broadly 

 expanded and reflected, somewhat auriculated at the posterior angle, 

 slightly radially fluted and marked by rather strong concentric in- 

 cremental lines. Inner peristome only moderately expanded, reflected 

 over and adnate to the outer. Breathing pore on the parietal wall near 

 the posterior angle. Operculum with a rather heavy granular cal- 

 careous deposit on the inner two-thirds of the turns. 



Races of this species are found from La Jagua south to the Costa- 

 iiera San Vicente. 



Sr .S^n Andm 



Figure 85. — Distribution of tlie .subsiiecies of Turrithijra (Titrrithi/ra) deceotor: (1) 

 deceptor; (2) persimilis ; (3) vicentensis ; (4) scalaris. 



Distribution of the subspecies of T. {2\) deceptor is shown in 

 ficure 85. 



KEY TO THE SUBSPECIES OF TURRITHYRA (TURRITHYRA) DECEPTOR 



Shell conspicuously spirally banded scalaris 



Shell not conspicuously spirally banded. 



Spaces between spiral thre.-^ds wider than threads. 



Axial ribs paler than ground color vicentensis 



Axial ribs not paler than ground color persimilis 



Spaces between spiral threads not wider than threads deceptor 



