270 THE ANTARCTIC MANUAL, 
Bovrevencrivipx, and was taken at stations 146 and 147 and else- 
where: in fact it seems to be widely distributed in the Atlantic and 
Southern seas. It occurred in considerable numbers, and this is, 
indeed, a characteristic of its family. (vii.) Hyocrinus bethellianus, 
Wyv. Th., the sole living representative of the genus, belongs to 
another essentially abysmal genus and to the family Hrocrrvw., 
It was taken at station 147, and possibly again near the equator. 
It thus appears that of the thirteen species of stalked Crinoids 
known from abysmal depths, but two are recorded from sub- 
Antarctic seas. A fair number of shallow-sea forms were also taken 
in this region. 
Class V.—HoOLOTHURIOIDEA. 
This group plays a large part in the Zoology of the deep sea. 
Here it is not the case of an isolated species or genus adopting the 
depths of the ocean as its habitat, but a large group, regarded by Théel 
as a third division equivalent to the Arona and Pepara (into which, 
until the date of the Challenger investigations, the Holothurioidea were 
divided), live as true deep-sea forms, and live nowhere else. This 
group Théel called the ELastropa. More modern classification places 
the members of the group in the family Hzrioup., one of the six which 
together constitute the Order. The #zpmnp% not only occur in a 
great number of species which increase in numbers from 50 fathoms 
dewn to 2900, but the number of individuals is also large, and they 
probably form a considerable proportion of the population at great 
depths. They are very diverse in appearance, and often bizarre in 
shape, unlike more typical Holothuroids. They tend to lose their 
radial symmetry, and become flattened, or even concave, ventrally, 
and rounded above. The body is often produced laterally into a 
flattened rim, which may have local extensions. Tube feet occur 
only on the ventral radii, and are often paired, giving the animal an 
appearance of segmentation. 
The following species occurred in the sub-Antarctic area:— 
(.) Psychropotes lovent, Th., at station 146; (i1.) P. longicauda, Th., 
at stations 156 and 157 in our area, and at station 298 further north. 
It seems to be a variable species, and attained in one instance the 
gigantic length of 260 mm. (iil.) Oneirophanta mutabilis, Th., at 
stations 146, 157, 160 and, outside the area at stations 244, 281, 
299, 325. A widely distributed and very abundant form. (iv.) 
‘Lindia purpurea, Th., one specimen from station 146 and one from 
station 157. (v.) £. willesméest, Th., one complete and three injured 
specimens from station 156, (vi.) #. incerta, Th., four incomplete 
