GASTROPODA. 9 
RIssoI4. FRAUDULENTA. 
(PL. IL, fig. 3.) 
Shell small, ovate-elongate, scarcely rimate, thin, semi-transparent, dull, dirty 
whitish ; whorls 5, convex, divided by a slightly oblique suture, ornamented with fine 
spiral strize, crossed by the still more delicate lines of growth ; protoconch large, smooth, 
globose; aperture ovate, occupying rather more than a third of the entire length ; 
outer lip thin ; columella margin very slightly reflexed, united above to the labrum by 
a thin callus. 
Length, 2°5 millim. ; diam., 1°5 ; aperture, 1 in length. 
Hole 3. 123 fathoms. Stones and gravel. 
The principal features of this shell are the spiral striz, convex whorls, and dull 
surface. 
RISSOIA GELIDA. 
(Pl. IL, fig. 5.) 
Shell ovate, acuminate above, imperforate, dirty whitish, ornamented with fine 
spiral liree ; spire obtusely conical; whorls 5, very convex ; apex smooth; suture deep, 
a little oblique ; aperture broadly ovate, rather large, occupying about five-twelfths of 
the entire length of the shell; labrum thin, a little effuse, especially at the base ; 
columella narrowly reflexed, united above to the labrum by a thin callosity. 
Length, 3 millim. ; diam., 1°75 ; aperture, 1°25 long. 
Operculum normal, paucispiral, thin, without any process. 
Holes 3, 4,12. In 122-41 fathoms. 
The spiral threads are five or six in number on the penultimate whorl, and about 
twelve on the last. 
RISSsOIA DESERTA. 
(Pl. IL, fig. 1.) 
Shell ovately conical, imperforate or scarcely rimate, dirty whitish, semi-transparent, 
dull, sculptured only with fine strive of growth ; whorls 5, convex, narrowly margined 
beneath the suture; spire conical, blunt at the tip; suture very slightly oblique ; 
aperture almost circular; peristome thin, continuous, outer margin simple, columellar 
edge narrowly reflexed. 
Length, 2°5 millim.; diam., 1°75 ; aperture, 1 long. 
Winter Quarters, Feb. 20, 1902, and March 19, 1902, 10 fathoms. 
In form rather like R. gelida, but at once separable on account of its smooth 
surface. 
Rissola GLACIALIS. 
(Pl. IL, fig. 4.) 
Shell ovately conical, narrowly perforated, white, smooth, glossy, exhibiting only 
fine strie of growth; whorls 5-6, very convex, and consequently separated by a deep 
VOL II. x 
