THE CYCIjOPIIORID LAJSTD MOLLUSKS OF AMEIRICiA 47 



riblets extend feebly over the umbilical wall. Aperture circular, 

 slightly irregular as far as its external plane is concerned ; peristome 

 thickened and marked by concentric lamellae of about the same ex- 

 pansion all around. Operculum typically farcimoid. 



The type, U.S.N.M. No. 535941, was collected by Dr. Abbott at 

 El Rio, which is between Constancia and Jarabacoa, Dominican 

 Republic, at an elevation of 4,000 feet. It has 7.5 whorls and 

 measures: Height, 19.0 mm.; greater diameter, 7.7 mm. 



This I consider to be the small form described by Pfeiffer as Cyclo- 

 stoma orhignyi var. y. It differs markedly from the other two known 

 Haitian species by its much smaller size, much more inflated whorls, 

 and much heavier ribbing. 



FARCIMOIDES DOMINGOENSE, new species 



Plate 9, Figuees 1-3 



Shell cylindroconic, stout, varying from wax color to pale brown 

 on the last turn. Nuclear whorls? The early postnuclear whorls 

 gain rapidly in size and are fairly well rounded; the later ones are 

 decidedly flattened. They are all narrowly shouldered at the sum- 

 mit and marked by slender, sigmoid, retractively curved axial rib- 

 lets, which are about as wide as the spaces that separate them on the 

 early turns and wider on the last. These riblets render the summit 

 of the turns slightly crenulated. Suture well constricted. Periph- 

 ery well rounded. Base moderately protracted, openly umbilicated, 

 and marked with a strong cord at the outer junction of the umbilicus, 

 which is deeply constricted at its umbilical edge and less so dorsally. 

 Aperture subcircular in a wavy plane; peristome thick, a little nar- 

 rower on the parietal wall than on the rest. Operculum, typically 

 farcimoid. 



The type, U.S.N.M. No. 535940, was collected by Parker in the 

 Dominican Republic. It has 6.4 whorls remaining and measures: 

 Height, 28.8 mm. ; greater diameter, 12.0 mm. 



Two other lots before us are also without specific locality data. 

 All these are readily distinguished from F. orhignyi (Pfeiffer) by 

 their much more cylindric form and much stouter outline. 



FARCIMOIDES ORBIGNYI (Pfeiffer) 



Plate 9, Figures 4-6 



1851. Cyclostoma orhignyi Pfeiffee, Proc. Soc. London, vol. 19, p. 149. 



1852. Cyclostoma orhignyi Pfeiffer, Martini-Chemnitz Conchylien Cabinet, vol. 1, 



sect. 19, p. 272, pi. 37, figs. 3, 4. 



Shell almost cylindroconic, varying in color from unicolor to wax 

 yellow, with the last whorl with a reddish orange band, which is 

 separated from the summit and base by a paler area. Peristome 



