CUBAN ANNUIjARiroAE — TORRE AND BART&CH 245 



sists of feeble indications of threads, which render the axial riblets 

 wavy. Of these, 7 appear to be present on all the whorls. Suture 

 strongly constricted. Periphery strongly rounded. Base marked 

 by the continuation of the axial ribs and by 7 spiral threads, which 

 render the riblets slightly scalloped. Aperture almost circular; 

 peristome double, the outer broadly expanded, deeply notched on the 

 middle of the inner lip and reflected posterior to this, and appressed to 

 the base, completely covering the umbilicated area; the outer peri- 

 stome is marked by slender concentric lamellae; inner peristome 

 slightly exserted. Operculum typically tudorid. 



The type, U.S.N.M. No. 356392, was collected on El Toro, Sierra 

 de Limones, Pinar del Rio, by Henderson and Bartsch in 1916. It has 

 almost 4 whorls and measures: Length, 7.6 mm.; greater diameter, 

 4.5 mm ; lesser diameter, 3.5 mm. 



The peculiar thimble-pitting of the nuclear whorls will distinguish 

 this species from all the other western Cuban annularids. It is dis- 

 tinguished from Limadora proper by the possession of a breathing 

 pore and a double peristome. 



LIMADORA, new genus 



Annularids in which the nuclear whorls are pitted and rough like 

 a rasp, characters which distinguish this group from all the other 

 members of the family, for in the rest the nuclear whorls are either 

 smooth or only microscopically granulose. The operculum is typically 

 tudorid, i. e., the whorls are provided with a lamella which rises from 

 the inner edge of the turns, and which is reflected outward to parallel 

 the basal chondroid plate, and which extends to the outer edge of the 

 whorls, thus forming a continuous surface without a channel between 

 the turns, in which the chondroid basal plate is visible. The lamella is 

 marked by retractively curved threads. Peristome simple. Breath- 

 ing pore absent. 



Type: Limadora tollini (Ramsden). 



KEY TO THE SPECIES OF LIMADORA 



Shell of trochid outline tollini 



Shell not of trochid outline. 



Shell elongate-ovate or elongate-conic. 



Umbilicus narrowly perforate garciana 



Umbilicus imperforate scabrata 



LIMADORA TOLLINI (Ramsden) 



Plate 22, Figures 1, 4 



1915. Rhytidopoma tollini Ramsden, Nautilus, vol. 28, pp. 135-136, pi. 6, fig. 5. 

 1920. Ramsdenia tolleni Henderson and Bartsch, Proc. U. S. Nat. Mus., vol. 

 58, p. 79. 



Shell of trochid outline, flesh colored with a yellowish tinge. Nu- 

 clear whorls almost 2, strongly rounded, rough lilve a coarse rasp. 



