OB^ THE KERGUELEN REGION OF THE GREAT SOUTHERN OCEAN. 353 



LIST I. 



Metazoa procured by the Challenger in the Deep-water Area of the 

 Kerguelen Region, in depths exceeding 1260 Fathoms. 



This list contains all the species and varieties of marine Metazoa described and 

 recorded in the Challenger Report from eight deep-water Stations in the Great Southern 

 Ocean, south of the Indian Ocean, traversed by the Challenger during the cruise from 

 the Cape of Good Hope to the Antarctic Circle and Australia, viz., Stations Nos. 146, 

 147, 152, 153, 156, 157, 158, and 160, lying between latitude 42° 42' to 65° 42' S. and 

 longitude 45° 31' to 134° 10' E., the depths varying from 1260 fathoms at Station 152 to 

 2600 fathoms at Station 160. For the sake of brevity this region has been called the 

 deep-water area of the Kerguelen Region. At the most southerly Station (No. 153) the 

 dredge was used, the trawl being sent down at the other seven Stations. The species 

 not known to occur outside the region represented by these eight Stations, nor therefore 

 in depths less than 1000 fathoms, are indicated in this list by an asterisk *. 



Monaxonida : 



Axinella erecta 1 (Carter). 

 *Cladorhiza 2 moniliformis, 3 Ridley and Dendy. 



# ,, (?) tridentata* Ridley and Dendy. 

 *Esperella mammiformis, 5 Ridley and Dendy. 



* Esperiopsis* profunda, 1 Ridley and Dendy. 



1 Axinella erecta is a very variable species. — (Ridlet and Dendy, Zool. Chall. Exp., part 59, p. 182.) 



2 Although the different species of Cladorhiza vary very much in external form, yet the different modifications of 

 the main skeleton, upon which the external form of the sponge depends, are easily derivable from one common primary 

 type, and afford interesting instances of adaptation. — (Ridley and Dendy, Zool. Chall. Exp., part 59, p. 86.) 



3 Cladorhiza moniliformis is a form of the very greatest interest, and affords a good example of radial symmetry in 

 a Monaxonid Sponge. It was a question with us whether or not this species should form the type of a new genus, but 

 we finally decided not, as no essential changes are necessary to derive it from the more typical species. ... It is, 

 of course, by no means impossible that perfect specimens of Cladorhiza moniliformis may have a branching stem witli 

 a head at the end of each branch.— (Ridley and Dendy, Zool. Chall. Exp., part 59, pp. 91, 92.) 



4 In the arrangement of its skeleton Cladorhiza tridentata stands quite alone in the genus, and as this is generally 

 such a good guide, it seems very doubtful whether it ought to be admitted as a Cladorhiza, but for the sake of con- 

 venience we shall retain it here for the present, placing it at the end as a doubtful species. — (Ridley and Dendy, Zool. 

 \Chall. Exp., part 59, p. 96.) 



6 Esperella mammiformis is a very beautiful little species, and affords another good example of a deep-sea sponge 

 with a definite external form.— (Ridley and Dendy, Zool. Chall. Exp., part 59, p. 63.) 



6 Several of the species of the genus Esperiopsis are remarkable for their well-defined external forms, which serve 

 is excellent guides by which to separate them from one another and from others of the genus. . . . The distribution 

 )f the genus Esperiopsis is very wide, both vertically and horizontally, but it appears to prefer deep water in temperate 

 >r boreal seas— (Ridley and Dendy, Zool. Chall. Exp., part 59, p. 77.) 



7 Esperiopsis profunda is interesting on account of the great depth (1600 fathoms) from which it was obtained, and 

 Yitn this must again be associated the presence of a definite external form.— (Ridley and Dendy, Zool. Chall Exp., 

 iart 59, p. 8 1.) 



