THE NAUTILUS. 



PhilomyiHs, presenting no generic difference from tlie well-known species of that 

 genus. Heynemann (1884) has referred them to Avion, but he could not have 

 examined them sufficiently, and was no doubt misled by the figure in Man. de 

 Mai. (1827), pi. xli. That they are really Blainville's types need not be doubted, 

 as they agree with his figures in outline, and his original description, notwith- 

 standing that he misunderstood the characters of the slug, is sufficient to show that 

 he had not an Avion before him. He refers to the absence of a shell and the 

 genital orifice at the base of the right tentacle. The outline of the figure, and 

 especially the anterior portion of the mantle, suggests at once a Philomyciis. The 

 supposed Avioti-Vike mantle indicated in the figures is really due to an outline of 

 some of the internal organs, visible on account of the transparency of the slug. 

 The figures in Journ. de Phys., November, 1817, show how the mistake began, fig. 

 4 having even a sort of spiral coil in the middle of the anterior part of the mantle. 

 The figure of Z. elfovtiana in Man. Mai. is the same outline, but apparently 

 patched up from an Avion ater, with altogether fictitious rugae on the back. 

 Feriissac's figure is after one of those in Journ. de Phys., and is fairly recognizable. 

 Altogether I think it must be held that Blainville described and figured his 

 genus Limacella sufficiently for recognition, and as it antedates Philomycus by 

 three years, the name must be used. Limacella, Brard, 1815, need not be con- 

 sidered, as it is identical with Litnax, Linne, 1707. The synonymy of Limacella, 

 Bl., will accordingly stand : — 



LiMACEi.l.A, Blainville. 



1817. Limacella, Blainville, " Mem. sur qu'elq. Moll. Pulm." Journ. de Phys, 



Dec. 1817, p. 443 (text), and Nov. 1817, figs. 4, 5. 

 1820. Philomycus, Rafinesque, Ann. of Nat. p. 10. 



1820. Eumelns, Rafinesque, Ann. of Nat. p. 10. 



1824. Meghima/ium, v. Hass. Bull. Univ. Sci. iii. p. 82. 

 1842. Lncilaria, Bens. Ann. & Mag. Nat. Hist. ix. p. 486. 

 1842. Tebennophovus, Binney, Bost. Journ. Nat. Hist. iv. p. 171. 

 1864. Pallifeva, Morse, Journ. Porll. Soc. i. 8, fig. 5, pi. lii. fig. 6. 



It does not seem necessary to recognize more than one genus here, though V. 

 Ihering (Nachr. d. m. Ges. 1889) recognizes three — Philomycus, Pallifeva, and 

 Meghitnatium. Pallifeva may be conveniently retained as a subgenus. 



The species of Limacella are as follows : — 



Limacella laciifovmis, Blainv. 



1817. Limacella laciifovmis, Blainv. Journ. de Phys. Dec. p. 444. 



1821. Limacellus lactescens, Ferussac, Hist. Nat. Moll. pi. vii. fig. 1. 



1825. Limacella elfovtiana, Blainv. Man. de Mai. et de Conch, p. 464. 



This appears to be distinct from any species since recognized. The British 

 Museum types may be biiefly described as follows: — 42 millim. long; respiratory 

 orifice 7 millim. from anterior border of mantle. Sole, lat. 7 millim. Entirely 

 greyish-white; mantle pellucid, semitransparent, finely granulofe. Sole slightly 

 ochreous, unicolorous. A distinct groove round the edge of the foot. Liver pale 

 chocolate. 



Gray in 1855 (Cat. Pulm. p. 158) has referred this species to Philomycus. 



