332 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. .[122] 



the expanded club, bears minute serrate suckers, at first in six rows, 

 decreasing to two toward the end. The extreme tip bears a small group 

 of minute, smooth-edged suckers. The largest suckers of the club are 

 decidedly constricted below the margin, and then swell out at the basal 

 portion. The edge of the horny rim is divided into very numerous 

 small, incurved, and crowded denticles, nearly equal in length, but part 

 are thickened and obtuse, while the rest are more slender and acute. 

 Diameter of the largest suckers 6.5 mm ; of the largest in the second row, 

 5.5 mm ; of the largest in the lateral rows, 3 mra to 4 mm ; of the largest smooth- 

 rimmed marginal suckers, 2 ,nm to 2.5 mm ; of the smooth -rimmed suckers 

 of the wrist, 1.5 mm to 2 n,m . 



Sessile arms stout, trapezoidal, tapering to slender tips, and bearing 

 two rows of numerous suckers. All the arms on the left side are an 

 inch or more longer than the corresponding right ones. The dorsal and 

 ventral arms of the same side are about equal, and decidedly shorter 

 than the two lateral pairs, which differ but little in length. Web about 

 two-thirds as broad as the length of the arms, uniting the upper three 

 pairs together, and as a narrowing border extending along their sides 

 to the tips. The lower lateral arms have a thin, crest-line membrane on 

 their outer median surface, commencing at the basal fourth and extend- 

 ing nearly to the tips. The ventral arms are united together, toward 

 the base, by a web, which is also joined to the main web, in the median 

 plane. A narrow outer web, arising from the outer angles of the arms, 

 also unites all the arms together for a short distance above their bases. 



The suckers (Plate XXIV, figs. 5, a, b) are all similar in form. The 

 larger ones on the dorsal arms are, perhaps, a little larger than those on 

 the lateral and ventral ones. The largest are subglobular, laterally at 

 tached, and gibbous ; the aperture is small, usually with three or four flat, 

 blunt, or rounded lobes or denticles on the outer margin, with none on the 

 inner margin. The pedicels of the larger suckers are very stout at base, 

 tapering up to their attachment on the lower side of the sucker, where 

 they are small and slender. The largest suckers of the dorsal arms are 

 5 mm in diameter; their apertures, 2 mm ; length of pedicels, 4 mm to 5 mm . 

 The largest suckers on the ventral arms are not so large as those on the 

 others ; the largest are 4 mro in diameter. Only a few suckers (five or six), 

 and these of very small size and nearly in one row, extend below the 

 level of the ventral web, which is attached along the inner margin, in- 

 side the row of suckers. The larger ventral suckers are depressed and 

 oblique, with a very one-sided horny ring, which has a small, oblique 

 aperture, with about three bluntly rounded, slightly prominent lobes or 

 denticles on the outer margin, while the inner margin is smooth. 



The membranes about the mouth are arranged nearly as in Omma- 

 strephes. The mouth is surrounded externally by a broad, elevated, 

 smooth, dark chocolate-brown buccal membrane or collar, which is 

 prolonged into six angular lobes, corresponding to all the intervals 

 between the arms, except those between the second and third pairs; 



