THE CYCLOPHORID LAND M0LLUS1K9 OF AMERICA 167 



CALAPEROSTOMA HIDALGOI (Crosse) 



Plate 21, Figubes 10-12 



1866. Ct/clophorus hidalgoi Ceosse, Journ. Conchyl., vol. 14, p. 354, pi. 14 fig. 4. 

 1897. Amphicyclotus hidalgoi Kobelt and Moixendoket, Nachrb. deutschen 

 malak. Ges., vol. 29, p. 139. 



Shell of medium size, depressed-helicoid, covered with a chestnut- 

 brown periostracum, a little paler on the early whorls. Nuclear 

 whorls almost 2, smooth; the succeeding turns well rounded and 

 marked by low, rounded spiral cords,, of which 8 are present on the 

 penultimate turn. These cords disappear on the last half of the 

 last turn. They are a little narrower than the spaces that separate 

 them, and the first is at a little distance below the summit. The axial 

 sculpture consists of coarse incremental lines, which are almost rib- 

 like. Those on the last whorl near the summit produce a series of 

 feeble elongated nodules. Periphery well rounded. Base well 

 rounded and marked by 8 weak, very low spiral cords, which are 

 separated by mere impressed darker lines. The umbilicus is broad 

 and its wall is marked by strong axial ribs. Aperture subcircular, 

 oblique, slightly angulated at the posterior angle, bluish white 

 within; peristome simple. Operculum corneous, with central nu- 

 cleus, concave externally with a central papillus on the inside. 



The specimen described and figured, U.S.N.M. No. 316134, is one 

 from the Cuming collection from New Granada (Colombia). It has 

 5 whorls and measures: Height, 15.2 mm.; greater diameter, 25.9 

 mm. ; lesser diameter, 19.4 mm. 



This species resembles G. cousini (Jousseaume) by having the spiral 

 sculpture on the upper surface evanescent on the last turn, and by 

 having the umbilical wall axially ribbed; it differs from it in being 

 much smaller. 



CALAPEROSTOMA CUMINGI (Sowerby) 



Plate 21, Figubes 20-22 



1832. Cyclostoma cumingii Soweeby, Proc. Zool. Soc. London, 1832, p. 32. 



1842. Cyclostoma cumingii Reeve, Couchologia systematica, vol. 2, p. 99, pi. 85, 



fig. 19. 



1843. Cyclostoma cumingii Soweeby, Thesaurus conchyliorum, p. 108, pi. 24, 



figs. 68, 69, 69*. 



1847. Cyclophorus cumingii Pfehtee, Zeitschr. Malak., vol. 4, p. 108 



1848. Cyclostoma cumingii Pfeiffeb^ Martini-Chemnitz Conchylien Cabinet, vol. 



1, sect. 19, p. 82, pi. 12, figs. 1-3. 

 1897. Amphicyclotus cumingii Kobelt and Mollendoeff, Nachrb. deutschen 



Malak. Ges., vol. 29, p. 139. 

 1935. Aperostoma (Calaperostoma) cumingii Pilsbet, Proc. Acad. Nat. Sci. 



Philadelphia, vol. 87, p. 4. 



Shell very large, depressed-helicoid, ground color soiled white; 

 the early turns rose-red. There is a very broad chestnut-brown zone 



