ABYSMAL FAUNA. 249 
Class II.—AcaLepH® (ACRASPEDA). 
The Schyphomeduse are represented by two species in our region. 
(viil.) Periphema regina, Haeck., of the family Pzrrearirro2, of the 
sub-order PEROMEDUSA. It was taken in fragments at station 156, and 
was avery large form, measuring 180-200 mm. in diameter. (ix.) 
Atolla wyvillit, Haeck., one of the family Epzrriox of the sub-order 
DIScoMEDUSA, taken at station 157, and again in the South Atlantic 
at station 318, is one of the most interesting Meduse brought home 
by the Challenger. Haeckel regards it as the remains of an extinct 
ancestral form of the DiscoMEDUS and as indicating the close connec- 
tion of this group with the PERoMEDUS& and CUBOMEDUS. 
Of the eighteen deep-sea Medusz described by Haeckel, it thus 
appears that six, or one-third, have been captured in the Antarctic 
region. It is, of course, not absolutely certain that all the specimens 
were taken at tbe depths. Some may have entered the dredge in its 
way upwards. Still, Haeckel thinks that of the genera just mentioned, 
Peetis and Aginura amongst the Hydromeduse, and Periphema and 
Atolla amongst the Scyphomeduse, have characteristics which suit 
them to an abysmal mode of life; and moreover, that they show 
by their primitive structure a remote phylogenetic origin. The 
families to which these genera belong have probably been deep-sea 
dwellers for a very long period of time. 
Class ITI.—Actinozoa. 
(A.) ALCYONARIA. 
The sub-order PENNATULACEA, the most highly organised is at the 
same time the most typically bathybial of the five Aleyonarian sub- 
divisions. They are rarely met with in shallow water, and at least 
one-half of the genera described are deep-sea forms. Two families, 
the Uusrriormsx and the Proropritipa, are characteristically abysmal, 
but the latter is not represented in our area. The family Uusszevnms« 
is represented by (x.) Umbellula carpenteri, Kéll., taken at stations 
156 and 157. The axial polype is, in this family, drawn out to form 
an enormously long stalk, a characteristic feature of many deep-sea 
animals (c.f. the stalked Crinoids and Tunicata). (xi.) U. magniflora, 
KOIL, from station 147, attained a total length of 740 mm. The 
genus Umbellula has the widest distribution of-all the Pennatulids, 
stretching along the Atlantic and Pacific from pole to pole. 
Of Alcyonarians, other than Pennatulids, two deep-sea species 
