372 PROCEEDINGS OF THE NATIONAL. MUSEUM Vol.89 



The specimen described and figured, U.S.N.M. No. 356296, is a 

 cotype received from Dr. de la Torre and collected by Arango at 

 Maisi, Oriente Province. It has 4.4 whorls and measures: Length, 

 7.8 mm.; greater diameter, 10.6 mm.; lesser diameter, 8.7 mm. 



A larger specimen from the same locality, U.S.N.M. No. 356297, 

 has 4.8 whorls and measures: Length, 9.7 mm.; greater diameter, 

 11.8 mm.; lesser diameter, 8.9 mm. 



ANNULARIA (ANNULARELLA) ARQUESI, new species 



Plate 51, Figures 4-6 



1866. Cyclostomus romeri var. Pfeiffer, Malakozool. Blatter, vol. 13, p. 63. 



1867. Cyclostoma arquesi Arango, nomen nudum, MS., Repert fisico natural Isla 



de Cubana, vol. 2, p. 270. 

 1876. Cyclostomus romeri Pfeiffer, Monographia pneumonopomorum viventiTim, 



suppl. 3, p. 176, in part. 

 1898. Colobostylus arquesi Kobelt and Mollendorff, nomen nudum, Nachr. 



Deutsch. Malak. Gesell., vol. 30, p. 192, in part. 



Shell turbinate, pale straw colored, a Httle deeper within the 

 aperture. Nuclear whorls almost 2, well roimded, microscopically 

 granulose except for the last portion of the last turn, which shows the 

 begimiing of the postnuclear sculpture. Postnuclear whorls inflated, 

 well rounded, the first one marked by 84 slender, threadhke axial ribs. 

 On the remaining turns the axial sculpture becomes separated into two 

 elements; one, strong lamellar axial ribs, which are developed into 

 slender auricles at the summit; the other, fine threads less than one- 

 fourth the size of the coarser, occupying the spaces between the 

 coarser. The latter vary from 3 to 7 in number. Of the stronger 

 ribs, 46 occur on the second turn and 50 on the last. Suture narrowly 

 channeled. Periphery inflated, obscurely angulated. Base short, 

 openly umbilicated, moderately well rounded, marked by the con- 

 tinuation of the axial riblets and by a strong spiral cord, which marks 

 the junction of the umbilicus and the base. There are two slender 

 spiral threads posterior to the stronger cord on the base. The umbili- 

 cal wall is marked by the continuation of the axial riblets, which here 

 become crowded and somewhat enfeebled, and 4 spiral threads. 

 Aperture broadly oval; peristome double, the inner poorly defined, 

 reflected over the outer and appressed to and coextensive with it on 

 the outer lip; the outer broadly, flaringly expanded, forming a moder- 

 ately strong auricle at the posterior angle, and adnate to the preceding 

 turn on the parietal wafl. Operculum typicaUy annularid. 



A cotype received from Dr. de la Torre, collected by Arango at 

 Barigua, north coast of Baracoa, Oriente Province, U.S.N.M. No. 

 356294, has 5.3 whorls and measures: Length, 13.0 mm.; greater 

 diameter, 12.1 mm.; lesser diameter, 9.7 mm. 



