224 PLEUROBRANCHCEA. 



P. MECKELII Blainville. PL 53, figs. 81, 82, 83, 84, 85. 



Body oblong, very convex, pale brownish-gray with numerous 

 spots or marbling of blackish-brown over the whole upper surface, 

 the sole almost black, the posterior pedal gland whitish gray. In 

 alcohol the color fades to a very pale gray, dark spots indistinct, sole 

 vermiculate with blackish. Mantle covering only the median part 

 of body, not projecting or sharply defined on the left side and be- 

 hind, narrowly overhanging on right side ; in front produced forward 

 in a crescentic head-piece with laterally projecting processes, fore 

 margin serrate ; folded into a permanent excurrent siphon on the 

 right side behind. Rhinophores situated on mantle, wide apart, 

 truncate, slit and rolled; gill small, inserted behind middle of 

 mantle, mainly adnate, bipinnate. Female genital pore on a papilla 

 at anterior insertion of gill ; male orifice or penis in front of it. 

 Rostrum, in alcoholic specimens, extremely large and protruding 

 far in front. Foot oblong, subtruncate in front, tapering and 

 rounded behind, having a gland on the sole behind, which excretes 

 through a duct opening on a horn-like papilla on the upper surface 

 of the tail. Shell none, but a large shell-cavity present. 



Length of alcoholic specimen with protruded rostrum 55, breadth 

 21 mill. 



Palermo, Sicily (Phil.) ; Naples (Phil., Cantraine) ; Gulf of Mar- 

 seilles (Vayssiere). 



Pleurobranchcea LEUE, De Pleurobranchsea novo Molluscorum 

 Genere, 1813, pp. 1-12, plate. 



? Pleur. balearicus Laroche, CUVIER, Regne Auim., ii, (1817), p. 

 396, footnote (nude name, the identity of which with P. meckelii is 

 surmised by de Blainville). 



Pleurobranchidium meckelii Meckel, BLAINVILLE, Diet. Sci. Nat., 

 xxxxi, p. 376 (1826); Man. de Malac., p. 471, pi. 43, f. 3 (false 

 reference to Meckel's Beytrage vergleich. Anat.). 



Pleurobranchidium meckelii DELLE CHIAJE Memorie, iii, p. 159, 

 pi. 40, f. 11-17 (1828). 



Pleurobranchcea meckelii Lewe, PHILIPPI, Enum. Moll. Sicil., ii, 

 p. 88. 



Pleurobranchcea meckelii Leue,* DESHAYES, in Cuvier's Regne, 

 Anirn., Moll., p. 89, pi. 32, f. 2, 2a. BERGH, Res. Camp. Sci. 

 Albert I, fasc. iv, pi. 4, f. 96-99. 



Pleurobranchidium meckelii Blainv., DESH., Trait. Elem. de Con- 

 chy 1., pi. 91, f. 1, 2. 



