MUSEUM OF COMPARATIVE ZOOLOGY. 93 
much swollen plates, having deep furrows between them ; in centre a group 
of six primary plates, separated by a row of irregular smaller plates ; outside 
of these is another circle of ten equally large plates, of which the brachial 
ones separate the inner ends of the radial shields. In each interbrachial space 
there is also a large marginal plate. Radial shields longer than broad, outer 
edge much wider than inner, joined without, but widely separated within by 
a large rounded plate. Length to breadth 2:1. On the under surface the 
plates are not so much swollen, and more regular ; in each interbrachial space 
are about three concentric rows, of from three to five plates each. Genital 
plates long and rather wide, with outer end wider than inner ; along the free 
edge is a close row of fine, even, tooth-like papille, which become somewhat 
longer and wider as they pass upward to form the arm-comb. Three arm- 
spines short, blunt, and equally distant from cach other. On first two sets of 
pores four tentacle-scales on each side ; the third has three on each side; the 
fourth, one on the outside and three on the inside ; a little beyond the disk 
there is only one on the inside. Color in alcohol, white. 
Station 169, 700 fathoms, 4 specimens. 
Ophioglypha ponderosa sp. nov. 
Plate II. Figs. 52 - 54. 
Special Marks. — Disk-plates high and excessively swollen. Upper arm- 
plates rising in a high sharp ridge. Arm-spines minute, close-set, and like 
little blocks. 
Description of an Individual (Station 232).— Diameter of disk 32 mm. 
Width of arm at disk 6 mm. Mouth-papille square, flat, crowded, forming a 
continuous row with the scales of the mouth-tentacles, four or five on each side, 
with three or four longer and pointed papille at angle of jaw. Mouth-shield 
long and narrow, with outer end much rounded, lateral sides having a slightly 
re-entering curve, and a short blunt angle within ; length to breadth 5.7 : 3. 
Side mouth-shields long triangular, outer edges broader ; inner ends tapering, 
where they meet. Under arm-plates broad hexagonal, with outer and inner 
ends straight, and short angles on the sides ; the first plate is similar, but not 
so large as the others; farther out on the arm they become diamond-shaped. 
Side arm-plates swollen, with outer edge curved, not meeting either above or 
below. Upper arm-plates narrow, very highly arched, forming a sharp ridge ; 
length to breadth about equal, wider without than within, four-sided, with 
sides nearly straight. The upper surface of disk is covered by angular plates, 
excessively swollen and lumpy, and compactly soldered ; the plates in centre 
being smallest. Radial shields longer than wide, with edges irregularly curved, 
meeting without, diverging inward, where they are separated by a large plate 
of about the same size and shape; in the interbrachial space, besides numerous 
smaller plates, is one roughly triangular, with one angle inward ; on the lower 
interbrachial space the scales are not so much swollen ; there are about half a 
