24 BULLETIN 181, UNITED STATES NATIONAL MUSEUM 



FARCIMEN (FARCIMEN) AURICULATUM (Orbigny) 



Moderately large shells of very elongate-ovate outline. Early 

 whorls flesh colored or orange in one race ; the last or last two whorls 

 purplish brown. Nuclear whorls about 1.3, small, well rounded, 

 smooth. Postnuclear whorls well rounded, appressed at the summit, 

 marked by fairly regularly developed, slender, retractively curved 

 axial riblets, which on the last whorl are almost sigmoid ; these riblets 

 are narrower than the spaces that separate them. In addition to this, 

 the whorls show distantly, irregularly distributed, small, round pits 

 suggestive of F. (F.) alutaceum ([Menke] Pfeiffer). Suture mod- 

 erately constricted. Periphery well rounded. Base slightly pro- 

 tracted, moderately openly umbilicated and marked like the spire. 

 Aperture subcircular; peristome broadly expanded, except that of 

 the parietal wall, much thickened, with the posterior edge of the 

 reflection of the outer lip sharp. The peristome of the inner lip is 

 decidedly produced, which lends to the aperture an earlike appear- 

 ance, hence the name. It does not approach the preceding whorl but 

 is separated from it by a large gap. A knoblike thickening may be 

 present at the posterior termination of the peristome of both the inner 

 and outer lip. Operculum typically farcimenid. 



We are recognizing four subspecies, three of which appear confined 

 to the southwest side of Santa Clara and southeast of Matanzas 

 Provinces, while the fourth stretches from the north coast at Cardenas 

 southward to Coliseo and San Miguel. 



KEY TO THE SUBSPECIES OF FARCIMEN (FARCIMEN) AURICULATUM 



Peristome very much thickened senectum 



Peristome not very much thickened. 



Early whorls orange clenchi 



Early whorls pale. 



Shell large, height more than 29 mm bicolor 



Shell smaller, height less than 26 mm auriculatum 



FARCIMEN (FARCIMEN) AURICULATUM SENECTUM, new subspecies 



Plate 5, Figukes 1(>-18 



Two specimens from Cayo Carenas, near Cienfuegos, collected by 

 Henderson appear to be semifossil. They differ very greatly from the 

 other subspecies in having the peristome enormously thickened and 

 decidedly effused on the columellar side. 



The type, U.S.N.M. No. 535911, has 5 whorls remaining and meas- 

 ures : Height, 26.5 mm. ; greater diameter, 14.1 mm. 



