AMPHIBULIMA. 239 



of the last half whorl rapidly descending. Spire rather slender, its 

 length contained 4J to 4| times in that of the shell. Aperture large, 

 irregularly oblong, the outer lip somewhat blunt, strongly arcuate 

 above, retracted or waved backward at the position of the slight 

 "shoulder. "; somewhat effuse below. Columella arcuate, thin. 



Alt. 19, diam. 10.5, length of aperture 15, length of spire 4.3 mill. 



Alt. 18.5, diam. 10, length of aperture 14.7, length of spire 3.8 mill. 

 Dominica, 1,000 ft., on bananas (A. D. Brown). 



A. tigrina Lesseur, A. D. BROWN, American Naturalist, xv, 

 1881, p. 57. 



Less fragile than A. pardaUna, with less obtuse apex and irreg- 

 ularly arcuate outer lip, which curves transversely at the posterior 

 insertion, and is waved backward where the arcuate upper arc joins 

 the straighter outer portion. The nepionic shell is very finely longi- 

 tudinally wrinkled, the wrinkles slightly decussated by spiral lines. 



A. RAWSONIS Bland. 



Shell ovate-oblong, thin, with rather rib-like stria3 irregularly de- 

 cussated by impressed lines parallel with the suture ; shining, scarcely 

 pellucid, rather dark horn-colored, ornamented with a very few red- 

 dish spots. Spire short, rather obtuse, rufous ; with a reddish line 

 beneath the impressed suture. Whorls 3, the last convex, much 

 deflexed at the aperture; columella callous, receding. Aperture 

 oblique, oblong-oval, coerulescent within ; peristome simple, slightly 

 thickened, right margin sinuous, columellar margin arcuate. Length 

 18, diam. 10 mill.; aperture 14 mill, long, 9 wide (Bland}. 



Island of Montserrat (Sir Rawson W. Rawson). 



Amphibidima rawsonis BLD., Ann. of the Lye. Nat. Hist, of N. 

 Y., xi, p. 199 (1875). BINNEY, t. c., p. 187, pi. 13, f. C (genitalia), 

 pi. 14, f. E (teeth); Ann. N. Y. Acad. Sci., iii, p. 118, pi. 13, f. H, 

 G (teeth). 



This species is most nearly allied in form to A. pardalina Guppy, 

 of Dominica. Its radula is characterized by the very great size of 

 the central teeth. I have not seen a specimen. 



Subgenus RHODONYX Fischer, 1873. 



Rhodonyx FISCHER, Journ. de Conchy]., 1873, p. 325; type 

 Succinea rubescens Mastoyyra ANCEY, Le Naturaliste, iii, Oct., 

 1881, p. 484, type Succtnea rubescens. 



