236 REPORT OF COMMISSIONER OF FISH AND FISHERIES [26] 



They are, except the ventral, compressed trapezoidal in form, and 

 taper very gradually to slender, acute tips; their inner faces, along the 

 proximal half of their length, are occupied by two alternating rows of 

 large, obliquely campanulate suckers, with contracted apertures, sur- 

 rounded by broad, oblique, thin, horny, marginal rings, much broader 

 on the outer side than on the inner, and armed with strong, acute teeth 

 around their entire circumference, but the teeth are largest and most 

 oblique on the outside (Plate IV, figs. 5-8). The suckers gradually 

 diminish in size to the tips of the arms, where they become very small; 

 those toward the tips of the arms appear to have been denticulate on 

 the outer side, and entire, or nearly so, on the inner margin. The ven- 

 tral arms still have, as they show in the photograph, the inner face 

 much broader than it is in the others, especially near the base, and 

 they are more nearly square than any of the others. Their suckers are 

 more numerous, farther apart transversely, and closer together in the 

 longitudinal series, there being about 4G on the proximal half (3G inches) 

 of each, while on each of the subventral arms there are only about 30 on 

 the corresponding portion ; the suckers also diminish rather abruptly in 

 size at about 26 to 30 inches from the base, beyond which they are 

 scarcely more than half as large as those on the second and third pairs 

 of aims, at the same distance from the base; it is probable, judging 

 from the small specimen (No. 24), that all the suckers of the ventral 

 arms were denticulate only on the outer margin. The largest of these 

 suckers are said by Mr. Harvey to have been about an inch in diam- 

 eter when fresh. The largest of their marginal rings in my possession 

 are lG mm to 17 mm in diameter at the serrated edge, and 18 mm to 21 mm be- 

 neath. 



The horny rings are yellowish horn- color, oblique, and more than twice 

 as high on the back side as in front. A wide peripheral groove runs 

 entirely around the circumference, just below the denticulated margin; 

 it is narrower and deeper on the inner side. On the inner side of the 

 largest kind (c, d, e, //) the edge is nearly vertical, and the denticles point 

 upward or are but slightly incurved; but on the outer side the edge and 

 denticles are bent obliquely inward; along the lateral sides the edge is 

 more or less incurved, and the denticles are inclined more or less forward, 

 toward the inner edge of the sucker (figs. 5, G, Ga). The denticles are golden 

 yellow, or when dry silvery white; those on the outer and lateral mar- 

 gins are largest, flat, lanceolate, with sharply beveled lateral edges and 

 acuminate tips ; those on the front margin are shorter, narrower, acutely 

 triangular, and in contact at their bases. On the largest of these suckers 

 there are forty-eight to fifty denticles. Some of the suckers (figs. 7, 7a, 8) 

 of rather smaller size (a, b) are more oblique, with the outer side of the 



7.5 inches in circumference, and one of the lateral ones (perhaps one of the third pair) 

 8 inches. The marginal membranes and crests had decayed, apparently, before the 

 arms were preserved. The terminal portions of the arms are also gone, so tbat theirreal 

 lencrth cannot be i:iven. 



