REPORT OF COMMISSIONER OF FISH AND FISHERIES. [88] 
suckers grade gradually into the large or primary ones, both iu size and 
form; they are, however, armed with four or five very sharp incurved 
teeth on the outer margin, of which the median one is longest, while 
the inner margin is usually entire. They are very oblique and one-sided 
in form. The membrane around the rim of all the suckers is thickened, 
but most so on the basal ones; it usually recedes behind the large median 
tooth, leaving there an emargination. 
The outer buccal membrane is not very large; its inner surface is 
closely covered with lamelliform folds and wrinkles; its border is pro¬ 
longed into seven acute angles, from which membranes extend to the 
opposite arms, going to the upper sides of the second and fourth pairs 
of arms, aud to the lower side of the third pair; but the seventh angle 
is in the median dorsal line, and the membrane from it bifurcates, one- 
half going to the inner side of each dorsal arm. Immediately around 
the jaws there is a circular, thickened, rugose oral membrane, with a 
strongly lobed edge, while its inner surface is radially wrinkled and 
covered with scattered rounded verrucm. A plain fold intervenes be¬ 
tween this and the outer buccal membranes. The beak and pharynx 
can be protruded its whole length, when in use. At such times the oral 
membranes are partially unfolded. 
The jaws are sharp and incurved at tip, reddish brown to brownish 
black in color, with the posterior borders of the lamimie whitish and 
translucent. The upper mandible has a much incurved tip, with the 
cutting edges regularly curved, and with a shallow notch at their bases, 
beyond which the anterior edges rise into a broad, obtuse lobe or low 
tooth, by which the hardened and dark-colored part, as seen by trans¬ 
mitted light, has the form of a sharp angular tooth, but its actual pro¬ 
jection anteriorly is but slight, because the translucent edge beyond it 
rises to about the same level. The lateral-posterior borders of the 
frontal laminae are sinuous and incurved in the middle; the palatine 
lamina is broad, with the posterior lateral edges incurved and sinuous. 
The lower mandible has the extreme tip strongly incurved, forming a 
slight notch close to the tip, below which the edges are slightly incurved 
or nearly straight, with a decided V-shaped notch at the base; the an¬ 
terior edges, beyond the notch, form a triangular tooth of the inner 
laminae, but this is obscured, unless viewed by transmitted light, b^ the 
outer alar lamina, which rises at its anterior edge, where‘it is translu¬ 
cent, nearly to a level with the tooth; the inner ends of the alae are wider 
than the middle, and broadly rounded ; the gular laminae are short, nar¬ 
rowed posteriorly, with their inner edges incurved, and with a thickened, 
prominent ventral carina. 
The jaws of a large specimen measure as follows: Upper mandible, tip 
to posterior end of palatine lamina, 22 mm ; to dorsal end of frontal lamina, 
16 mm ; to posterior lateral edge of same, 9 mm ; to base of cutting edge, 5 mm ; 
inner edge of palatine lamina to dorsal end of frontal lamina, 17 mm ; lower 
mandible, tip to inner end of aim, 13 mm ; to ventral notch of aim, 4 mm ; 
