M \ORODONTES. 31 



M. ODONTOSTOMrs (Sowerby). PI. 13, figs. S">, Sf, ST. 



Shell rimate-perforate, cylindric-fusiform, solid, uniform light 

 chestnut-brown ; surface somewhat glossy, densely and sharply stri- 

 ated obliquely, and seen under a lens to be closely cut by spiral lines. 

 Whorls about 6^, convex, rapidly increasing, the last becoming free 

 in front, impressed behind the outer lip, with three pits in the im- 

 pression, the latter half of the base pinched into a very strong though 

 blunt keel, defining a Hat basal area, pitted behind the lip, and sepa- 

 rated from the umbilical excavation by a shorter keel. Umbilical 

 cavity ample. Aperture oblique, oblong, obstructed by 8 lamellae 

 and folds: a marginal, triangular tooth on the straight parietal mar- 

 gin, an oblique, slightly calloused columellar plication, crossed below 

 by a transverse columellar lamella, a blunt, low-conic basal fold, and 

 within the outer lip three compressed folds, the median (upper pala- 

 tal) obliquely descending as it passes inward, the lower palatal en- 

 tering, the suprapalatal small. Peristome pink or lilac-tinted, broadly 

 expanded and reflexed and completely free throughout. 



Length 38, diam. 12, longest axis of aperture 14 mill. 



Length 35-37J, diam. 13^, longest axis of aperture 13^ mill. 



Brazil : Corcobado near Rio Janeiro, and Macahe (Paz). 



Bulimns odontostoina SOWB., Zoological Journal, i, p. 59, pi. 5, f. 



3 (1824). REEVE, Conch. Icon., pi. 38, f. 228 PFK., Monogr. ii, 



p. 82 ; iii, 367 ; iv, 435 ; vi, 75 ; Conchyl. Cab., p. 138, pi. 16, f. 1-3. 

 HIDALGO, Journ. de Conchy]. 1870, p. 51. Helix odontostoma 

 WOOD, Ind. Testae. Suppl., pi. 7, f. 28. Papa odontostoma GRAY, 

 Ann. of Philos., n. ser., ix, p. 413. DESHAYES in Fer., Histoire, ii, 



p. 204, pi. 163, f. 1 Macrodontes odontoslomus Sowb., W. G. BIN- 



NEY, Ann. N. Y. Acad. Sci., ii, p. 114, pi. 10, f. H (jaSv and denti- 

 tion). Pupa erythrostoma MENKE, Synopsis, edit. 2, p. 32, 1830 

 (new name for B. odontostoma, Sowb.). Olausilia gargantua DESH. 



in Lam., An. s. Vert., viii, p. 214 Odontostomus gargantula BECK, 



Index, p. 54 Macrodontes sowerbeyii SWAINS., Malacology, p. 334 



(1840). 



The pink aperture is broader and shorter than in the other species 

 with a long, arcuate, basal keel, and it is less closed by the teeth. 



This species has been supposed to be the Helix gargantua of Fer- 

 ussac, but the original description, " Bouche armee de gros plis ou 

 dents alongees . . . Coquille aussi rare que singuliere, de plus de 

 deux pouces de longueur," indicates that the original gargantua was 

 0. pantagruelinus. 



