Boone, Molltisca, Cruises of "Ara" and "Alva" 351 



nent. The web is bilaterally symmetrical, well developed, uniting 

 the proximal region of the arms for a distance not quite equiva- 

 lent to one-fourth of the arm length. The arms in the "Alva" 

 series of specimens are in the order 2, 3, 4, 1, except in the largest 

 two specimens, where it is 3, 2, 4, 1, the third and second pairs 

 here being nearly equal. 



The suckers are quite large, set closely in alternate series. The 

 largest suckers occur in the sixth to tenth series of the second and 

 third pairs of arms, where in the largest specimens they attain a 

 diameter of fourteen percentum of the mantle length, while in 

 smaller specimens the ratio is only ten percentum. The individual 

 suckers are large, circular, with a deep central pit, saucer-like, 

 with strong, fine radiating grooves and the margin distinctly ex- 

 panded in two borders. 



The mantle aperture is quite wide, the funnel free for half its 

 length, well developed, with the locking ridge continuous from 

 side to side in all but two specimens. TTie funnel organ varies 

 in shape, being a complete W-shape, or incomplete, having the 

 outer arms of the W shorter than the central portion, or vice versa. 

 Seven to eleven filaments are to be found in each demibranch. 



The radula are variable, the rachidian tooth being constantly 

 symmetrical, each series consisting of three to five teeth, but show- 

 ing variation in the type of periation. 



The hectocotylus of the male is said by Robson (1928) to pos- 

 sess considerable variation. The one male present in the collec- 

 tion from the Society Islands has the calamus near the last sucker 

 and is typical. In the large females the oviducal gland was mod- 

 erately large, in one specimen being considerably dilated. 



The texture of the skin is coarse, variously roughened with 

 pointed granules, knob-like verrucae, or grouped smalled verrucae 

 around a central knob, the degree and kind of markings undoubt- 

 edly being due to state of preservation and mode of killing which 

 the specimen has undergone. The general colour of the present 

 dead specimen is deep gray to purplish black dorsally with paler 

 suckers in conspicuous contrast on the ventral side. Cirrhi are 

 usually present about the eyes and sometimes on the dorsal of the 

 body. 



Varieties: For discussion of the numerous varieties of the 

 species, consult Robson (1929). 



