OSCANIUS. 213 



The above species are apparently distinct and well-characterized ; 

 a number of others, 0. purpureus, 0. dilatipes and 0. reticulatus are 

 of doubtful status. 



O. TESTUDINARIUS Cantraine. PL 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 14 cm. 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 striae 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 (Vayssiere). 



Pleurobranchus tuberculatus DELLE CHIAJE, Memorie su laStoria 

 Notomia degli Animali senza Vertebre del Regno di Napoli, 

 iii, 1828, p. 154, pi. 40, figs. 1-10. Pleurobranchus tubereulatus 

 Meek., CANTRAINE, Malac. Med. et Litt., p. 89 (not of Meckel, 

 1808). R. forskahli DELLE CHIAJE, t. c., p. 154, pi. 41, fig. 11 

 {not of Riippell & Leuckart, 1828). Pleurobranchus mammilla- 

 tus Schultz, PHILIPPI, Enum. Moll. Sicil., i, 1836, p. 112 (not 

 of Quoy and Gaimard, 1834). Pleurobranchus testudinarius 

 CANTRAINE, Bull, de 1'Acad. Roy. des Sciences et Belles-Lettres de 

 Bruxelles, No. 11, December, 1835, p. 385 (1836); Malacol. Med. 

 t Litt., p. 88. PHILIPPI, Enum. Moll. Sicil., ii, p. 86, pi. 20, f. 1 ; 

 pi. 21, f. 1. FISCHER, Man. de Conchy!., p. 571, fig. 335 (copied from 

 Philippi). VAYSSIERE, Journ. de Conchyl., 1880, p. 209, pi. 7, f. 



