THE CYOLOPHORID LAND MOLLtTSlKS OF AMEKICA 277 



1852. Cyclotus duffiarius Pfeiffee, Monographia pneumonopomorum viventium, 



vol. 1, p. 29. 

 1857. Cyclotus (Cyclotus) dufflamis Chitty, Proc. Zool. Soc. London, 1857, p. 



142. 

 1S98. Neocyclotus (Plcctocyclotus) dufflanus Kobelt and Moixedorff, Nachrb. 



deutschen malak. Ges., vol. 29, p. 138, reprint. 



A translation of Adams's Latin diagnosis follows : 



Shell large, discoid, reddish white; whorls 4.5, cylindrical; umbili- 

 cus broad, profound; margin (aperture) simple. Divergence, 150°, 

 greater diameter, 47.5 mm.; lesser diameter, 35.2 mm.; height, 22 

 mm. This species is dedicated to Officer William Duff, well versed 

 in Jamaican conchology. 



Of this species Chitty says {loc. cit.) that C. dufflanus C. B. Adams 

 "is not a Jamaican, but a South American species— ^t^e Adams and 

 Mr. Bland, who found duplicates in South America." 



No huge shell like this is known from Jamaica, and there seems 

 little doubt but what Chitty's statement is correct. It is possible 

 that if the type were known or available this might prove to be an 

 Aperosto7mi, from Panama, related to Aperosto7n,a {Aperostoma) 

 giganteumn (Reeve). 



INCERTICYCLUS BRAZILIENSIS (Gray) 



Plate 39, Figure 13 



1839. Cyclostoma Irasiliense Geay, The zoology of Captain Beechey's voyage, 

 p. 147, pi. 38, fig. 32. 



We have not seen specimens of this species and so copy Gray's 

 description and figure: 



"Shell of a rather depressed orbicular form, thin, white, opaque ; 

 whorls four or five, transversely striated, striae sharp and close-set; 

 suture deep; aperture circular, peritreme thin, sharp edged; umbilicus 

 large; operculum shelly, thick, double, smooth within and with a 

 very fine spiral line outside. 



"Found in abundance in shady places near Rio Janeiro." 



The figure shows a keel limitmg the edge of the umbilicus. We 

 know nothing from the mainland with such a structure. 



INCERTICYCLUS PROMINULUS (Orbigny) 



Plate 39, Figures 7-9 



1837. Cyclostoma prominula Oebigny, Voyage dans l'Am4rique M^ridi- 

 onale . . ., vol. 5, pt. 3, p. 362. 

 Shell very depressed-helicoid, soiled white. The nucleus consists 

 of about 114 inflated, strongly rounded, smooth turns, which form a 

 conspicuous prominent apex. The postnuclear whorls are strongly 

 rounded with the summit falling a little below the periphery of the 

 preceding turn. The last whorl may be solute for about one-tenth 



