26 BULLETIN 181, UTSTITEiD STATES NIATIO!NiAiL MUSETJM 



FARCIMEN (FARCIMEN) TORTUM (Wood) 



Plate 5, Fiqubes 10-12, 22-24 



1828. Turbo tortus Wood, Index testaceologicus, ed. 2, Suppl., p. 20, fig. 32. 



1828. Cyclostoma tortum Wood, ihid., p. 36, pi. 6, fig. 32. 



1851. Cyclostoma apertum Poey. Memorias sobre la historia natural de la Isla de 



Cuba, vol. 1, pi. 7, figs. 15, 16. 

 1854. Megalomastoma apertum Poey, ibid., p. 405. 



Shell of medium size, elongate-ovate. Early whorls wax yellow, 

 turning to brown on the last turn. Peristome white. Nuclear whorls 

 1.7, well rounded, smooth. Postnuclear whorls strongly rounded, the 

 early ones marked by very regular, very closely spaced, hairlike axial 

 riblets, which evanesce on the last turn. Faint indications of spiral 

 lirations are also present. Suture strongly constricted, rendered con- 

 spicuous by the very narrowly shouldered summit of the whorls. 

 The last whorl is rather long, bounded anteriorly by a low rounded 

 carina, which marks the outer edge of the moderately broad open 

 umbilicus. The umbilical wall is marked by axial threads, which 

 are stronger here than on the outside of the last turn. Aperture 

 oblique, subcircular; peristome very much thickened, reflected, nar- 

 rower on the parietal wall and the columella. Operculum typically 

 farcimenid. 



The two specimens figured, U.S.N.M. No. 516857, came from Los 

 Palos, Nueva Paz, Habana Province. They were collected by Arango. 

 One, a complete specimen, has 6.5 whorls; the other has 5.2 whorls 

 remaining. They measure, respectively: Height, 27.0, 23.5 mm.; 

 greater diameter, 14.0, 13.9 mm. 



There are 38 lots in the collection of the United States National 

 Museum, all of which fall within the range mentioned above. 



Wood's small figure has caused endless confusion. Most authors 

 believed that it represented what we are here calling Farcinien yseudo- 

 tortwm^ which occupies a region of eastern Cuba that was not explored 

 in 1828. The aperture as figured by Wood is not quite normal for 

 F. apertum Poey, a common species in Habana Province, but speci- 

 mens with the characters here depicted are not infrequent. The 

 swollen, overhanging middle whorl is also of not infrequent occur- 

 rence in F. apertum Poey, all of which leads us to believe that F. 

 tortum is without question Farcimen apertum Poey, which name it 

 must replace. 



In 1851 Poey {loc. cit.) gave two figures of what he called Cyclos- 

 toma apertum. Evidently through correspondence with Pfeiffer he 

 was led to believe that his figures represented a variety of F. auricu- 

 latum, for in 1854 {loc. cit.) he states that the figures were bad. Here 



