On Specimens 0/ Ceplialodiscus densus. 433 



Genus Leporillus. 

 L.apiculis,Uo\x\^*. 2- 53.10.22.15. S. Australia 



[F, atranc/e). Gould Coll. 



Geuus NoTOMYS. 

 N. cervi7ms, Gould. 53. 10. 22. 7. 29^ G' S., 14P E. 



(Sturt). Gould Coll. 

 ffouldi, Gould. 7. 1. 1. 135. W. Australia (J. 



Gilbert). Tomes Coll. 

 lonfficau(J(dus, (juuld. 44,7.9.15. Moore's II., VV. A. 



{J. Gilbert). Gould Coll. 



Genua Coniluiius. 

 C. constructor, Og. $. 63. 2. 20. 1. N.S.W. (G. C'a- 



leij). Linueau Society. 



XLII. — On Specimens of Ceplialodiscus densus drede/ed by 

 the 'Challenger' in 1874 at Kerguelen Island. By W. G. 

 KiDEWOOD. 



[Plate XII.] 



'J'llE genus Cephcdodiscus was founded upon material dredged 

 by tlie 'Challenger^ in January 1876 from Station 311 in 

 the Straits of Magellan ; the material was described in 1887 

 by M'lntosh and Harmer in the lleports of the ' Challenger' 

 Expedition (12), but preliminary accounts were published in 

 1882, 1883, and 1885 (10, 11, 8). For many years this 

 material of Cephalodiscus dodecaloplms remained the sole 

 representative of the genus, and it was not until 1903 that 

 Andcrsson (i) announced a rediscovery of Cephalodiscus by 

 the Swedish South-Polar Expedition, and Harmer (5) notitied 

 the securing of new species of the genus by the 'Siboga' 

 Expedition. Since tliat year numerous species have been 

 founded upon material obtained by the ^Siboga' Expe- 

 dition (6), by Dr. Gilchrist (13), by the 'Discovery' Ex- 

 pedition (9, 14), by the Swedish South-Polar Expedition ^2), 

 by Dr. Schepotieff (19), by the Second French Antarctic 

 Expedition (3, 4), by tlie Scottish National Antarctic Expe- 

 dition (7), and by the British Antarctic ('Terra Nova') 

 Expedition (16). 



Up to the present time sixteen species of Cephalodiscus 

 have been described, but some of the specific names may have 

 to be regarded as synonyms (see 16, p. 14, footnote). A 

 synopsis of all the species of Cephalodiscus at present knuwn 



* The Museum received from Gould two specimens of this animal, 

 though he stated that he had only one. It seems, therefore, advisable to 

 nominate the specimen that best tits the description as the lectotype. 



Ann. ii; Mag. N. Hist. Ser. i). Vol. viii. 28 



