Boone, Molltisca, Cruises of "Ara" and "Alva" 361 



female measures 73 millimeters over all. The male body is ovoid 

 or globose, measuring 29 millimeters long to the margin and 28 

 millimeters maximum transverse width. The head is slightly nar- 

 rower than the body in the male, but in the smaller female the head 

 is about as wide as the maximum width of the body, which is more 

 tapered distally and less globular. 



The mantle aperture is posterior to the eye on either side, by a 

 distance equal to one-half of the aperture width. The mantle aper- 

 ture is 17 millimeters wide in the male, where the total width is 

 22 millimeters. The funnel organ is comparatively short, that of 

 the male being 4.5 millimeters long, attached for 3.5 millimeters, 

 and about 4 millimeters wide, while in the smaller female the 

 funnel organ is 6 millimeters long, attached for 5 millimeters, very 

 slender and tapered distally. The funnel organ is W-shaped. 



The gills have an average of eight filaments. The gill surface 

 is very small. The inner demibranch is distinctly reduced, with the 

 longest filaments about one-fourth less than the total depth. 



The web is moderately developed, the first four sectors being 

 approximately subequal, while the hindermost sector is slightly 

 shorter than the others. The web has a depth of a little more than 

 0.35 of the arm length and is continued upon the arms for only a 

 little distance. 



The arms decrease in the order 1, 2, 3, 4, the first and second 

 pairs being subequal; the third and fourth pairs, successively 

 decreasing very little, being rather short. The suckers are very 

 small, being of a diameter of 1.2 millimeters on those suckers 

 located about opposite the web margin. The male hectocotylized 

 arm is shown in plate 152, inset figure. 



The male reproductive organs agree essentially with Prosch's 

 description and figure (1849) of these. The oviducts of this fe- 

 male contain eggs. 



The radula agree quite well with the typical Bathypolypus 

 arctica radula, figured by Robson (1931, fig. 58) . 



References : Octopus arcticus, Prosch, V., K. Danske Vid. Selsk. 

 Skr., 1849, ser. 5, vol. I, 6, 53 and plate. 



Bathypolypus arcticus, RoBSON, G. C, Monogr. Recent Cephalop. 

 Brit. Mus. Coll., pt. II, p. 286, pi. 6, figs. 1-2, text fig. 30b, 

 also 53-60 (with extensive synonymy). 



