380 Mr. A. L. Massy on Cephalopods 



grooves, the first two usually placed singly, remainder 

 arranged in pairs, the seventh or eighth pair (about centre of 

 web in type) usually the largest, gradually diminishing towards 

 tip, where they are very small but not reduced to papillae. In 

 the type the suckers extend to within about 2 mm. of the 

 extremity of each arm. Web much developed, extending about 

 one quarter the length of tlie arms. Maximum development 

 between the dorsal pairs, least development between the 

 ventral arras. Web not contiimed on arms. Buccal mem- 

 brane and mandibles apparently very small, almost concealed 

 in the type by the basal suckers. Sipiion moderately large, 

 extending rather more than one third of the distance between 

 pallial aperture and web between ventral arms. Mantle 

 bursiform and somewhat pointed posteriorly, its aperture 

 exactly the width of basal portion of head. Body firm. Tlie 

 calamus brachialis of the hectocotylized arm short and but 

 little projecting; ligula copulatoria narrow and pointed, the 

 deeply concave interior looking like a longitudinal groove, 

 and crossed by nine slightly defined laminte copulatoria. 

 Sperm-canal extending to umbrella-margin, quite shallow 

 and like a narrow gradually widening wdiite band, smooth 

 except for a few^ faint grooves at a little distance from the 

 calamus brachialis. The end of hectocotylized arm when 

 viewed in profile much resembles that of O.polyzenia *, except 

 that the point of the calamus brachialis is not quite so acute. 

 Colour much like that of P. profundieola, but of a warmer 

 tone. Dorsal surface of body, head, and web the darkest ; 

 arms, inner and under surface much lighter, with patches of 

 bluish grey on web between each arm on ventral side. The 

 only specimen of this graceful-looking form was taken in the 

 sprat-net on trawl at 707-710 fath. 



Dimensions. 



mm. 



Total length 206 



End of body to mantle-margin 29 



„ „ centre of eye 42 



Breadth ot body 30 



„ head 32 



Centre of eye to lateral edge of umbrella . . 50 



Length of calamus brachialis 1 



,, ligula copulatoria 3 



Breadth of ligula copulatoria 2 



Diameter of largest sucker 4 



Siphon projects above mantle-margin 15 



Diameter between eyes 26 



* Eeport on the Zoological Collections made in the Indo-Pacific Ocean 

 during the Yovage of H.M.S. 'Alert,' 1881-2. MoUusca (by E. A. Smith), 



pi. iv. A^ 



