REPORT OF COMMISSIONER OF FISH AND FISHERIES. [122] 
tlie 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 mm to 4 mm ; of the largest smooth- 
rimmed marginal suckers, 2 mm to 2.5 mm ; of the smooth-rimmed suckers 
of the wrist, 1.5 mm to 2 mm . 
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 XXIY, 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 ,um in diameter 5 their apertures, 2 n ““j length of pedicels, 4 mm to 5 mm . 
The largest suckers on the ventral arms are not so large as those 011 the 
others; the largest are 4 m,n 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- 
streplies. 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 j 
