MUSEUM OF COMPARATIVE ZOOLOGY. 75 
broader within, where they meet. First under arm-plate transverse oval, 
broader than long, often with lateral ends pointed ; second arm-plate four-sided, 
with corners much rounded ; the next three are pentagonal, with an angle in- 
ward, and outer edge curved ; beyond these the lateral sides become shorter, 
so that soon the form changes to very wide triangular, with a broad curved 
outer edge, and an obtuse angle inward. Side arm-plates broad, little swol- 
len, meeting below beyond the disk, separated above by upper arm-plates, 
of which the first is oval, with pointed lateral ends ; those beyond four- 
sided, broader without than within, outer side curved, lateral sides nearly 
straight. Disk flat, smooth, and very thin; upper surface covered with 
small, irregular, closely overlapping scales, with a row of larger scales 
along ‘the margin, Radial shields broad triangular, with edges rounded, 
separated widely by a group of disk-scales ; length to breadth 2.3; 2. On the 
under surface the scales are more uniform, and are arranged in irregular trans- 
verse rows, four to six in each row. The genital plate, except at its outer end, 
appears only as a narrow line, bearing a close row of short, square papilla, 
which become larger and more rounded where they form the arm-comb. 
Three short, bluntly pointed arm-spines, situated near the junction of the side 
with the under arm-plate. Seven square, close-set scales on each side of mouth- 
tentacle pores ; the next two pairs have four on each side; the next one usually 
three on the inside and two on the other; beyond the disk only one on the 
inner side. Color in alcohol, white. 
Station 237, 1875 fathoms, 10 specimens. 
Ophioglypha undulata sp. nov. 
Plate III. Figs. 61, 62. 
Special Marks. — Three very short, conical arm-spines, standing on middle 
of edge of plate. Disk-scales coarse and rather thick. Radial shields broader 
than long, and joined. Papillæ of arm-comb close-set, flat, and with rounded 
ends, 
Description of an Individual (Station 994). — Diameter of disk 19 mm. 
Width of arm close to disk, without spines, 2.3 mm. Mouth-papille four on 
each side, short and square and closely set, the outer one widest ; at angle of 
the jaw usually a cluster of three conical papille, Mouth-shield rounded tri- 
angular, much broader than long, with an obtuse angle within, and outer side 
slightly curved ; length to breadth 2.3: 2.3, Side mouth-shields nearly 
straight, rather long, and meeting fully within. First under arm-plate oval or 
rounded hexagonal, and wider than long ; the next longer than any other, axe- 
shaped, with long lateral sides re-enteringly curved and outer side curved ; those 
beyond grow rapidly shorter, and beyond the fourtlr are Separated by the side 
arm-plates, which are regular and scarcely swollen, and meet above and. below 
beyond the fourth upperarm-plate. First upper arm-plate wide, semicircular ; 
the rest diamond-shaped, with inner angle truncated and the outer more or less 
