152 THE VOYAGE OF H.M.S. CHALLENGER. 



Loligo, Lamarck/ 

 Loligo edulis, Hoyle (PL XXIIL). 



1885. Loligo edulis, Hoyle, Diagnoses IL, p. 186. 

 1885. „ „ Hoyle, Prelim. Eep. IL, p. 289. 



Habitat. — Yokohama, Japan. Purchased in the market. One specimen, ^ . 



The Body is moderately stout, being about three times as long as broad, cylindrical 

 in its anterior third, and tapering gradually to a bluntish point. The Jin occupies a 

 little more than half the length of the body ; it is rhomboidal, not quite so broad as long, 

 and broadest anteriorly to the middle ; the lateral angles are rounded. The mantle- 

 margin has a slight projection in the dorsal median line and a broad shallow sinuate 

 excavation ventrally. The siphon is of moderate length and bluntly pointed. 



Tlie Head has prominent rounded eyes, and the usual auricular crest and preocular pore. 



The Arms are unequal, the order of length being 3, 4, 2, 1, and about half as long as 

 the body. The j&rst are very slender and bear a distinct keel on the dorsal aspect ; the 

 second are thicker and triangular, and have a broad keel almost expanding into a web 

 on the lateral aspect ; the third are the stoutest, flattened from above downwards, 

 and distinctly keeled externally; the fourth are intermediate between the third and 

 second, triangular, and with a broadish web extending the whole way up the dorso- 

 lateral aspect. They all have a web up each side of the inner face. The suckers 

 (figs. 3, 4) are in two series, very oblique, and with slender conical peduncles, their size 

 varying with that of the arms on which they are situated ; the horny ring bears about 

 eight long square-cut teeth on its distal margin. The left ventral arm as usual is 

 hectocotylised, and bears proximally ten rows of suckers, then a minute sucker with an 

 exaggerated peduncle, and beyond this two series of long conical papillae (fig. 5). The 

 huccal membrane has the usual seven angles produced into long lappets, each of which 

 bears about eight suckers in two rows ; the outer lip is moderately thick, the inner 

 much thicker and marked with deep radial grooves. 



The Tentacles are about as long as the body, with flattened ste77is ; about one-third 

 their length is occupied by the club (fig. 6), which is only slightly expanded, has a 

 protective membrane on either side, but a dorsal web is present only at the extremity. 

 The central suckers (fig. 7) are about sixteen in number and about one-third larger than 

 the lateral ; the proximal are about ten, the distal are closely packed in four series. The 



1 Gwyn Jeffreys (Brit. Conch., vol. v. p. 130) gives "Schneider" as the authority for this genus, but without any 

 reference or even date. The only paper by that author bearing in any way upon the subject, which I have been able to 

 find, is one entitled Bemerkungen iiber die Gattung der Dintenfische (Schrift. Gesellsch. itaturf. Freunde Berlin, Bd. xi. 

 pp. 33-50, 1794). In it this passage occurs (p. 46), " Icb finde auch damit eine Zeichnung ganz iibereinstimmig, welche 

 ich von dem Lungenherze des Kalamers (Loligo) entworfen habe." This does not, however, seem to be of the nature 

 of a definition, and so I have followed the majority of writers in attributing the creation of the genus to Lamarck. 



