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



mounted upon long conical peduncles, whose bases are curved outwards, and a broad 

 membrane passes up the lateral aspect of the arm for about three quarters of its length. 

 The tentacular suckers (figs, 16, 17) are largest at the inner border of the club, and 

 there they are bounded by a narrow protective membrane, beyond which is a fin about 

 one -third as broad as the club. 



Promachoteuthis} Hoyle. 



Body short, rounded, with large broad fins, situated posteriorly. Mantle free 

 behind, as in Rossia ; siphon short, slender, and with everted margin ; valve ? 



Head small and narrow ; eyes not prominent. 



Arms long and conical, with two series of pedunculate spherical suckers. Tentacles 

 exactly resembling the arms at their origin ; their extremities wanting in the only 

 specimen. 



Gladius not removed from the single example. 



The definition of this new genus must be regarded as provisional ; the only known 

 species being represented by a single specimen, in describing which all that is known 

 about the genus will be stated. 



Promachoteuthis megaptera, Hoyle (PL XIV. figs. 10—14; woodcut 3). 



1885.. Promachoteuthis megaptera, Hoyle, Narr. ChaU. Exp., vol. i. p. 273, fig. 109. 

 1885. „ „ Hoyle, Diagnoses 11, p. 182. 



1885. „ „ Hoyle, Prelim. Eep. IL, p. 284. 



Habitat. — Station 237, south-east of Nosima, Japan, June 17, 1875 ; lat. 34° 37' N., 

 long. 140° 32' E. ; 1875 fathoms ; blue mud. One mutilated specimen, sex ? 



The Body is short, barrel-shaped, rounded behind ; the fin is large, transversely 

 elliptical, and extending beyond the end of the body posteriorly ; each half is wider 

 than long. The mantle-margin is transversely truncated. The mantle-connective 

 consists of a linear ridge on either side, fitting into an almond-shaped depression at 

 each side of the base of the siphon (fig. 11), which is short, slender, and has the 

 distal margin everted, like the neck of a flask ; the specimen was so small and 

 indifferently .preserved that the siphon was not opened to ascertain whether a valve was 

 present. 



The Head is very small and narrow, almost the whole of its sides being occupied 

 by the eyes, which are not prominent, but are covered with a transparent membrane, 

 and have a distinct pore at a point in front of and below each (fig. 10). 



1 In forming this name I have ventured to make use of Dr. Carpenter's very apt rendering of " Challenger " by 

 %p6fia.x''i (Narr. Chall. Esp., p. 311). 



