OSCANIUS. 213 



The above species are apparently distinct and well-characterized ; 

 a number of others, 0. purpureus, 0. dilatipes and 0. reticulatu* 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 strise 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 la Storia 

 e Notomia degli Animali senza Vertebre del Regno di Napoli, 

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

 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. 

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

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

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



