194 MALACOZOA. GASTEROPODA. NUDIBRANCHIATA. 



4. JEolis Leslidna. Leslie's JEolis. 



Body elongated, tapering behind, flat beneath, convex above ; 

 the medial bare space along the back very narrow, linear- 

 lanceolate, white, with an oval brown obtuse prominence about 

 the middle ; on each side about a hundred and sixty papillae, 

 disposed, in about thirty transverse rows, or, if examined when 

 the animal is in a state of repose, of about fifteen oblique 

 rows ; those near the middle of the back lanceolate, compressed, 

 rather obtuse, rugoso-undulate, those along the sides shorter, 

 linear, a little enlarged at the tip, their colour a faint pinkish 

 tint, margined and tipped with white ; a tuft of about forty 

 smaller papillae on each side, about and anterior to the upper 

 tentacula, which are conico-subulate, rather obtuse, granulate, 

 brown, at the end pale reddish-yellow, and arising each from 

 an oblong elevated brown space ; the anterior tentacula long, 

 subulato-setaceous, hyaline, with a white line in each, running 

 backward into a triangular white space before the upper ten- 

 tacula, and from which proceeds backward a medial narrow 

 white line, between the two elongated brown spaces mentioned, 

 expanding into a triangular white space, succeeded by the 

 brown dorsal prominence, which is margined by a curved white 

 line on each side, the two meeting behind it, in the tapering 

 white line which extends to the end of the body ; the margin 

 of the mantle thin, considerably extended ; the foot hyaline- 

 white, oblong, anteriorly rounded in a semicircular form, with 

 a small decurved tapering point on either side, the margins 

 very thin, undulated, the hind part gradually attenuated into 

 a point, having a small denticle on each side. Length an inch 

 and a-half. 



This remarkable, and prominently marked species, I first 

 found in the beginning of October, 1842, in crevices of the 

 rocks on the Girdleness, at Aberdeen. It being, in so far as 

 I can learn, not described, and certainly not by Dr. Fleming, 

 Dr. Johnston, or Mr. Alder, in their respective works or 

 memoirs, I have named it after my good friend James Leslie, 

 Esq., who was with me at the time of its discovery, and also 

 obtained a specimen. 



It resides in crevices filled with water, and when at rest 

 presents somewhat of the appearance of an Actinia with its 

 filaments extended. Its movements are very slow. When 

 advancing, it continually moves its anterior tentacula, appa- 

 rently using them as instruments of touch, and keeps the 

 upper extended divergently. The tentacula are retractile, and 

 the upper can be entirely withdrawn. The tail or hind part 



