224 SIMPULOPSIS PLATYSUCC1NEA. 



Similar to Sirnpulopfis in contour, but pallid, not plicate, and with 

 the apex smooth. 



I have not examined the apices of S. cznea or S. psidii ; but it is 

 smootli, without spiral striae, in S. portoricensis and $". dominiccnsis* 

 I look upon Platysuccinea as a group ancestral to Gceotis, and prob- 

 ably differing from the typical forms of Simpulopsis in some structural 

 characters besides the difference in the apex ; but only a thorough 

 study of the soft anatomy can justify such suspicions. 



Antilles : Porto Rico, S. portoricensis, S. psidii. 

 Haiti, S. dominicensis. 



Mexico : S. cenea. 



S. PORTORICENSIS Shuttleworth. PI. 63, figs. 67, 68. 



Shell semi-oval, ventricose, thin, glossy and nearly smooth, being 

 sculptured with slight irregular growth-wrinkles, stronger near the 

 aperture; somewhat translucent, very pale straw-tinted. Spire 

 prominent; whorls about 2^, very rapidly increasing and very con- 

 vex, the suture deeply impressed ; last whorl ventricose. .Aperture 

 rounded-oval, very oblique; peristome thin ; columella regularly ar- 

 cuate, thin. 



Alt. 12.6, diam. 13 mm. 



Alt. 12, diam. 15 mm. 

 Sierra de Luqidllo, Porto Rico, abundant on banana leaves (Blauner). 



S. portoricensis SHUTTL., Diagn. n. Moll., in Mittheil. der Natur- 

 forschenden Gesellschaft in Bern, 1854, p. 55 (separate copies, p. 

 147) PFR., Monogr. iv, p. 801; v, p. 22 CROSSE, Journ. de 

 Conchyl. 1892, p. 22 Platysuccinea portoricensis ANCEY, Le Na- 

 turaliste, iii, 1881, p. 484. 



Evidently allied to the smaller, less elevated, S. dominicensis. It 

 has not been figured before. 



S. PSIDII (Martens). PI. 63, figs. 63, 64. 



Shell imperforate, globose-conoid, thin, shining, striatulate, pale 

 buff. Whorls 3, a little convex, forming a conic spire with obtuse 

 apex; the last whorl inflated below. Aperture oblique, lunate-cir- 

 cular, occupying two-thirds the total length of the shell; upper mar- 

 gin somewhat straightened, produced in a si^moid curve ; columellar 

 margin thin, a little arcuate. Alt. 5, greater diam. 5, lesser 4, ob- 

 lique alt. of aperture 3^, width 3 mill. (Mart.^j. 



