24 
THE VOYAGE OF H.M.S. CHALLENGER. 
Mandibulse sat breves, margo masticatorius seriebns denticulorum compluribus 
armatns. Dentes linguales uniseriati, cuspide prominenti, utrinque denticulati. — Penis 
inermis. 
This novel form, for which I have established the generic name Cuthonella , somewhat 
resembles Crcitena 1 and Cuthona , 2 but differs in some comparatively essential points. 
The anus, instead of being situated upon the side of the body, is dorsal and slightly 
lateral. The dorsal papillae are not inflated ; they are set in transverse or oblique rows, 
which are crowded together so as to form a few larger groups. In the specimen that I 
examined the cnidophorous bags were absent. The foot is not very broad, its anterior 
margin is truncated. — The mandibles are somewhat short, the masticatory edge provided 
with several series of strong denticles. The radula has a single series of largish teeth, 
with a denticulate cutting edge. The penis is unarmed. 
The genus hitherto contains only one species. 
Cuthonella abyssicola, n. sp. (PL X. figs. 1-3 ; PI. XI. fig. 2 ; PI. XII. figs. 9-13). 
Habitat. — North Atlantic. 
One specimen was taken by Mr. John Murray with the trawl, on August 23, 1882, 
in the Faroe Channel, lat. 60° 5' N., long. 6° 21' W. ; in the cold area, from a depth of 
608 fathoms; bottom temperature 30° Fahr. 
The specimen had been preserved in alcohol and was somewhat contracted ; the total 
length was 2 ‘5 cm., the breadth 6 mm., and the height 6 mm. ; the length of the ten- 
tacles 2 ‘5 mm., of the rhinophoria 5 mm., and of the dorsal papillse as much as 7 mm.; 
the breadth of the anterior portion of the foot 8 mm., the length of the tail 2‘5 mm. 
The colour of the animal is of a uniform dirty-yellow, with the exception of the papillse, 
which are of a light brownish-grey but yellowish at the tip. The intestines are not 
visible through the walls of the body. 
The body is stout and elongated. The head rather flat, the tentacles short ; the longer 
rhinophoria wrinkled; the mouth-aperture is vertically elongated, and forms a perpendicular 
slit. The foot is large, with a truncated anterior portion ; the free edge of the foot projects 
about 1'75 to 2 mm. beyond the sides of the body ; on the anterior margin of the foot is a 
furrow ; the tail is rather short. The genital papilla is situated on the right side 
below the anterior half of the first group of papillse, and consists of a prominence with the 
projecting glans (PI. XII. fig. 10), behind which are two apertures placed upon a slightly 
excavated area (fig. 10). The median portion of the dorsal surface, which is free from 
papillse, is in the anterior half about as wide as the lateral papilla-bearing portions. The 
1 K. Bergh, Malacolog. Untersuch. (in Semper, Beisenim Archip. d. Philipp., Th. II. Bd. ii.), Heft i., 1876, pp. 9-12, 
Tab. iv. figs. 1-15. 
2 It. Bergh, Beitr. zur Kenntn. d. Moll, des Sargassomeeres, Verhandl. d. k. k. zool.-lot. Gesellscli. Wien, Bd. xxi., 
1871, pp. 1280-1283. 
