BULLETIN OE THE UNITED STATES FISH COMMISSION. 
360 
Class GASTROPODA. 
Subclass ANISOPLEURA. 
(Euthyneura). 
Order PTER0P0DA. 
Suborder THEC0S0MATA. 
Family CAVOUNIIDA. 
Genus CLEODORA Peron & Lesueur, 1810. 
Subgenus Creseis (Rang, 1828) Sowerby, 1833. 
Shell elongate-conical, straight, with a slightly gyrate sulcus extending from the apex to the 
aperture where it is produced as a point projecting above the oblique margin of the aperture dorsally. 
Type, Creseis spinifera Rang = C. subula Quoy & Gaimard. 
Creseis subula Quoy & Gaimard. Plate 57, fig. 1. 
Cleodora subula Quoy & Gaimard, Ann. Sci. Nat., x, p. 233, pi. vm, d, tigs. 1-3, 1827. 
Styliola subula Pelseneer, Challenger Pteropods, n, p.56,1888. 
The genus Creseis Rang was at first heterogeneous; one of the species was already the type of the 
genus Yaginella Daudin; the others comprised species of Cadulus, Creseis, and Styliola. In his Genera 
(pt. xxxix, Pteropoda, 1833), Sowerby figured C. subula as an example of the genus Creseis, and in his 
Manual (1839, and 2d ed., 1842) again cites it as a type and specifies among the characters of the 
genus the dorsal sulcus. Finally Gray (Fig. Moll. An., iv, p. 122, 1850) defined the genus in harmony 
with the preceding, and at the same time defined Styliola (as in the original diagnosis of Blainville) as 
including those species with a cylindrical section and simple circular aperture. It will therefore be 
seen that there is no good ground for the view taken by Fol and Pelseneer for referring the present 
species to Styliola. The sulcus is reflected by a ridge on the interior of the shell, and the cross section 
of the shell is “heart” shaped. As the original description of Styliola states that the cross section of 
that genus is circular, the type can not have been a specimen of this species. 
The present species is abundant in West Indian waters, and four specimens were obtained at 
Mayaguez, Porto Rico, by the Fish Commission party. 
Genus STYLIOLA (Lesueur, 1826) Gray, 1850. 
Shell elongate-conical, straight or curved, with a smooth surface, circular section and aperture; 
the plane of the simple aperture is at right angles to the longitudinal axis and the margin is not oblique, 
angular, or sulcate. 
Type, Styliola recta Lesueur. 
Styliola acicula Rang. 
Cleodora ( Creseis) acicula Rang, Ann. des Sci. Nat., xin, p. 318, pi. xvii, fig. 6, 1828. 
styliola redo (Lesueur, 1826) fide Gray, op. eit., 1850. 
Shell thin, aciculate, elongated, with a polished surface; often slightly curved or flexuous; with 
the apical termination slightly bulbous; transparent or whitish. 
Length, 10; max. diam. (at the aperture), 0.75 mm, 
Mayaguez, many dead specimens. 
The specimens agree with others, from the collection of Rang, in the National Museum. The 
slenderness of the specimens is variable, some being relatively stouter than others. 
Genus CUVIERINA Boas, 1886. 
Shells straight, subtransparent, subcylindrical, the apex sharp in the voting hut falling off in the 
adult state; aperture simple, slightly compressed. 
