A. E. VerriU — North American Cephalopods. 203 



The second division, 35'6'^'" in length, succeeds the small suckers. 

 Here the arm is flattened on the face, Avell-rounded on the back, and 

 provided with a sharp dorsal carina, increasing in width toward the tip. 

 It bears two alternating rows of about twelve very large serrated suck- 

 ers, and an outer row of smaller ones, on each side, alternating with the 

 large ones. The upper edge is bordered by a rather broad, regularly 

 scalloped, marginal membrane, the scallops corresponding to the 

 large suckers, while ]>rominent transverse ridges, midwaj^ between the 

 large suckers, join the uiembrane and form its lobes. On the lower 

 edge there is a narrower and thinner membrane, which runs all the 

 way to the tip of the arm. In one (the lower) of the rows of large 

 suckers there are eleven, and in the other ten, above 20™'" in diameter. 

 Tlie former row lias one additional sucker at its proximal end 15""" 

 in diameter, and three others at its distal end, respectively 16, 12, and 

 gmm j,^ diameter. The other row, of ten suckers, is continued by a 

 proximal sucker 10""" in diameter, and by two distal ones, respect- 

 ively 15 and 13""" in diameter. The number of 'large' suckers in 

 each row msij, therefore, be counted as 12, 13, or 14, according to the 

 fancy of the describer, there being no well-defined distinction between 

 the larger and smaller ones in either row. The largest suckers, along 

 the middle of the rows, are from 24'"™ to 30""" in diameter (Plate 

 XVI, fig. 3, <f). They are attached by slender but strong pedicels, 

 about 10'"'" long and 6 to 7'""' in diameter. The outer or back side 

 of these suckers is 16 to 18'"™ high; the front side 10 to 11""^', so 

 that the rim is about 24 to 28™'" above the surface of the arm. The 

 horny rings are 7 to 8'"™ high and have the aperture 20 to 23""" in 

 diameter. Each one is situated in the center of a pentagonal de- 

 pressed area, about 25'"™ across, bounded by ridges, which alternate 

 regularly, and interlock on the two sides, so as to form a zigzag line 

 along the middle of the arm These large suckers are broadly and 

 obliquely campanulate, but much less oblique than those of the short 

 arms ; the marginal ring is strong, and sharply serrate all around ; 

 the denticles are acute-triangular and nearly equal. The rings are 

 somewliat calcified and rather rigid when dried; a well-marked broad 

 groove runs around the entire circumference, below the bases of the 

 denticles. 



The small marginal suckers (fig. 3, b) are similar in structure, but 

 nnich more oblique, and mostly 9 to ii""" in diameter; they are 

 attached by much longer and more slender pedicels, and their mar- 

 ginal teeth are relatively longer, sharper and more incurved, espe- 

 cially on the outer margin. The peripheral groove is broad and deep. 



