384 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



ANNULAKIA (CHONDROPOMATUS) LATA ([Gnndlach] Pfelffer) 



Plate 57, Figures 4-6 



1858. Cyclostoma latum [Gundlach] Pfeiffeh, Malakozool. Blatter, vol. 5, p. 190. 

 1861. Chondropoma latum Bland, Ann. Lyceum Nat. Hist. New York, vol. 7, 



p. 27. 

 1920. Chondropoma {Chondropomatns) latum Henderson and Bartsch, Proc. 



U. S. Nat. Mus., vol. 58, p. 59. 



Sliell broadly helicoid, with well elevated spire, fle^ colored, the 

 nuclear turns and the first postnuclear turns pale brown. Nuclear 

 whorls 1.9, strongly rounded, inflated, very finely granulose. Post- 

 nuclear whorls strongly rounded, rather high, with a deep channel at 

 the summi^t, which is bordered anteriorly by a pronounced carina, 

 which is very feeble on the first postnuclear turn, but which increases 

 in strength from there on. The postnuclear whorls are marked by 

 strong, sublamellar, retractively slanting axial ribs, which are of 

 decidedly uniform, strength and spacing. The spaces between these 

 sublamellar ribs are marked by axial threads, which coincide with 

 the heavier sculpture in disposition. These threads vary from one 

 to five in number. The strong sublamellar axial ribs render the 

 shoulder near the summit weakly crenulated; they do not terminate 

 at the shoulder posteriorly, but extend into the channel at the 

 summit. Suture rendered very pronounced by a channel. Periphery 

 of the last whorl rounded. Base somewhat inflated, well rounded, 

 very deeply, openly umbilicated, the umbilicus occupying about one- 

 fifth of the diameter of the base. The base is marked by the contin- 

 uations of the axial sculpture described for the spire, while the um- 

 bilical wall is marked by 6 strong spiral cords, the first of which is 

 the strongest, and which marks the outer termination of the expanding 

 umbilicus, while the rest are successively a little weaker and closer 

 spaced. Posterior to the strong cord referred to as limiting the 

 umbilicus is another cord, which is considerably weaker. The junc- 

 tions of these spiral cords and the axial riblets form slender, elongated 

 nodules, having their long axis parallel with the spiral cords. Aperture 

 broadly pyriform; peristome double, the inner and outer coextensive, 

 except at the posterior angle, where the outer forms a conspicuous 

 auricle, while the inner forms a shelf. Sometimes there is a second 

 shelf between these two. Operculum thin, corneous, consisting of 4.5 

 turns with an excentric nucleus; the outer edge of the last volution is 

 thin and slightly upturned on the columellar border; the entire 

 surface, except the last two turns, has the outer surface covered with 

 a coating of small calcareous granules. 



This species comes from Santiago. The specimen figured is 

 U.S.N.M. No. 354945. A summary of the measurements of a series 

 of specimens before us yields the following data: 



