MUSEUM OF COMPARATIVE ZOOLOGY. To 
OPHIOSCOLEX Mitt. AND Troscu. 
Ophioscolex dentatus sp. nov. 
Plate VIX. Figs. 184 - 186. 
Special Marks. — Three or four short, blunt, flattened arm-spines. Numer- 
ous mouth-papille, whereof the outer are flat spiniform. One tentacle-scale. 
Description of an Individual (Station 142). — Diameter of disk 15 mm. 
Length of arm about 55 mm, Width of arm, without spines, close to disk 
2.7 mm. ‘There are seven mouth-papille on each side of an angle and one 
small and pointed at apex of jaw ; the three outer are flat spiniform, and much 
the largest and longest. On removing the skin the mouth-shield is seen to 
be wide triangular, having an obtuse angle within and outer corners rounded, 
Side mouth-shields long, narrow, and meeting within. Arms covered by a 
thick skin completely hiding the plates, which are obscurely indicated beiow 
by transverse furrows. On removing the skin, the under arm-plates appear 
longer than wide, with a curve without and a re-entering curve within ; the 
side arm-plates small and meeting neither above nor below, while the upper 
plates are only indicated by thin films of slightly calcified skin. Disk round 
and rather flat, covered with a soft naked skin variously wrinkled above and 
below.* Genital openings wide and long, extending from the mouth-shield to 
the edge of the disk. Three or four short, blunt, flattened arm-spines, equally 
spaced, about as long as an arm-joint ; the upper and undermost ysually a little 
the longest. One small rounded tentacle-scale on the inner side of the pore. 
Color in alcohol, light gray. 
Station 142, off Agulhas Bank, 150 fathoms, 12 4- specimens. 
Ophioscolex tropicus sp. nov. 
Plate VII. Figs. 190-192, 
Special Marks.— Seventeen to nineteen small, short, pointed close-set mouth- 
papille, occupying the entire margin of each mouth-angle. Whole animal cov- 
ered by a thick skin, through which appear the lower and side arm-plates, 
the mouth-shields, and (indistinctly) the scaling of the lower interbrachial space. 
Description of an Individual (Station 24). — Diameter of disk 8 mm. Width 
of arm close to disk, without spines, 1.3 mm. Eight or nine short, close-set, 
rounded mouth-papille, occupying the whole length of each side, and one larger 
and more pointed at apex of jaw. Mouth-shields much broader than long, in shape 
transverse oval ; length to breadth .6: 1.2. Side mouth-shields long, curved 
and narrow, broader without, tapering inward, where they do not quite meet. 
First under arm-plate very small, nearly square, the others larger, long hexago- 
nal, with outer side curved, lateral sides re-enteringly curved, and three inner 
sides short, Side arm-plates broad and thin, meeting near base of arm neither 
above nor below. The place of the upper arm-plates is occupied by thick skin, 
* It is not often so regularly wrinkled as in Fig. 185. 
