142 RECTOLEACINA. 



1866. O. POEYANA Pfr., 0. WRIGHTI Pfr., 0. TERES Pfr. 



1867. O. INCISA Pfr. 



Genus RECTOLEACINA Pilsbry, n. gen. 

 Streptostyla, Cuban species, of authors. 



Shell oleacinoid, oblong-fusiform, with a rather long spire, 

 covered with a glossy yellowish cuticle, marked with some 

 ill-defined varix-grooves, elsewhere smoothish or vertically 

 grooved; 2 to 2y 2 embryonic whorls smooth. Columella ver- 

 tical, convex in the middle, spirally twisted, the edge thick- 

 ened; outer lip arching forward in the middle. Type R. cu- 

 bensis Orb. 



Distribution, western Cuba. 



I believe this group to be parallel to Streptostyla but not 

 directly related to that genus. It is, in my opinion, a deriv- 

 ative from L&voleacina, from which it differs by the weaken- 

 ing of the columellar truncation, which is converted into a 

 curve. Much careful work remains to be done before the re- 

 lationships of L&varicella,, Lcevoleacina and Rectoleacina to 

 each other and to Varicella, Oleacina and Streptostyla can be 

 understood. The problem demands a comparative study of 

 the soft anatomy. 



a. Surface nearly smooth. 



b. Shell longitudinally streaked with brown, 25 to 30 



mm. long. R. cubensis. 



b 1 . Shell uniform except for a subsutural brown band, 



10 to 11 mm. long. R. suturalis. 



a 1 . Spire closely costulate ; length 20 to 25 mm. 



R. episcopalis. 



1. R. CUBENSIS (Orbigny). PI. 33, fig. 13. 



The fusiform-oblong shell is yellow with a greenish tint, 

 with irregularly-spaced, sinuous, longitudinal chestnut stripes 

 and streaks. The surface is glossy, marked with faint growth- 

 lines and a few impressed varix-grooves. Whorls 7J, slightly 

 convex, slowly and regularly widening. 



Length 30.5, diam. 10.7, aperture 17 mm. (Vinales). 



