OSCANIUS. 213 
The above species are apparently distinct and well-characterized ; 
a number of others, O. purpureus, O. dilatipes and O. reticulatus are 
of doubtful status. 

O. TESTUDINARIUS Cantraine. PI. 50, figs. 43, 44, 45, 46. 
Body elliptical, globulose, of an ochre red color. Mantle very 
large, thick, elliptical, with a sinus in front ; its whole surface bear- 
ing large polygonal tubercles, which, in the middle region of the 
back, each occupy a mesh of a rose-carmine network; mantle of 
deeper color than the rest of the body. Foot of the same form as 
mantle, but smaller, having a gland on the posterior-median part of 
sole. Gill free its entire length, very long, bipinnate, with a score 
of pinnules on each side of the nodose rachis. Anus behind the in- 
sertion of gill. Genital orifices distinct, situated in front of the gill, 
the penis a little anterior to the female orifice, and protected by 
two triangular membranes; renal pore near the female orifice. 
Large individuals measure, length 19 cm., breadth 14cm. Jaws 
lamellose, slightly reniform, composed of little pieces each with 9-11 
denticles in front. Radula having the formula 180 to 200.0.180 to 
200; teeth hooked, without denticulation. 
Shell auriculiform, very small, convex, with a slightly projecting 
spire and well-marked striz of growth, quite solid in consistence, 
pale amber colored. Length 6, width 3 mill. 
Gulf of Naples (Delle Chiaje, Cantraine, Philippi); Messina 
(Cantraine); Palermo (Monts.); Gulf of Marseilles, in 25 to 40 
meters ( Vayssiére). 
Pleurobranchus tubereulatus DELLE CHIAJE, Memorie su la Storia 
e Notomia degli Animali senza Vertebre del Regno di Napoli, 
lili, 1828, p. 154, pl. 40, figs. 1-10.—Pleurobranchus tuberculatus 
Meck., CanrraINnE, Malac. Méd. et Litt., p. 89 (not of Meckel, 
1808).—R. forskahlii DELLE CutaseE, t. ¢, p. 154, pl. 41, fig. 11 
(not of Riippell & Leuckart, 1828).—Pleurobranchus mammilla- 
tus Schultz, Pariippr, Enum. Moll. Sicil., i, 1836, p. 112 (not 
of Quoy and Gaimard, 1834).— Pleurobranchus testudinarius 
CANTRAINE, Bull. de Acad. Roy. des Sciences et Belles-Lettres de 
Bruxelles, No. 11, December, 1835, p. 385 (1836); Malacol. Méd. 
et Litt., p. 88.—Puitiepr, Enum. Moll. Sicil., ii, p. 86, pl. 20, f. 1; 
pl. 21, f. 1.—Fiscarr, Man. de Conchyl., p. 571, fig. 335 (copied from 
Philippi)—VayssIERE, Journ. de Conchyl., 1880, p. 209, pl. 7, f. 
