550 Dr. W. G. Ridewood on 



14. P. revoili, Robin*. — Erytbrea ; Somaliland ; British East 

 Africa ; Uganda. 



Id. p. capensis. Smith. — From Zambesia, south to Transvaal, Zulu- 

 laud, Natal, and Poudolaud, west to Mossamedes and 

 Benguela. 



16. P. damarensis, Pet. — Damaralaud ; Namaqualand ; Lake Ngami ; 



Tette. 



17. P. d. brockinam, K. A. — Erythrea; Somaliland. 



18. P. d. media, K. A. — Abyssinia (Harar). 



19. P. gambiensis, K. A. — Gambia. 



LXV. — On Sjjecimens o/ Ceplialodiscus ni*irescens supposed 

 to have been dredged in 1811 or 1812. By W. G. Ridewood. 



The genus Cephalodtscus v/as founded upon material dredged 

 by tlie 'Challenger" iu 1 87 G from a single locality (Station 

 311) in the Straits of Magellan. The full report upon that 

 material f was drawn up by Prof, W. C. M'Intosh and 

 Dr. S. F. Harrner, and published in 1887 (5)^ the species 

 being described as Cephalodiscus dodecalophus. 



Since then twelve new species of Cephalodiscus have been 

 described : — C. gracilis, C. sibogce, and C. levinseni, by 

 Harmer (3) ; C. nigrescens, by Laidcester (4) ; C. gilchristi 

 and C. hodgsoni, by Ridewood (6 and 7) ; C. (Bquatus, C. in- 

 (equatus, C. solidus, C. densus, and C. rarMS, by Andersson (i) ; 

 and C. indicus, by Schepotieff (9). 



Another species, somewhat resembling the C. rarus of 

 Andersson, is stated to have been obtained on the second 

 French Antarctic Expedition. The name given to it by 

 Gravier (2) is C anderssoni ; but since the author does not 

 enumerate its distinguishing features, the species cannot as 

 yet be regarded as more than a nomen nudum. 



Yet another species, of strongly marked facies, was 

 obtained by the ' Scotia ' during the Scottish National 

 Antarctic Expedition, when at Station 346 (lat. 54° 25' S., 

 long. 57° 39' W., depth 56 fathoms), in December 1903. 



* Bull. See. Philom. (7) v. p. 90 (1881). Name perhaps antedated by 

 Heuglin's Nycteris lahiata (N. Act. Ac. C. Leop.-Car. xxix. p. .5; 1861), 

 the type of which I have not yet seen. 



t The full report was preceded by a preliminary notice in the 'Annals 

 and Magazine of Natural History,' (o) x. 188i^ pp. .3.37-348, and another 

 iu the Keport of the British Association meeting of 1882 (published 1883, 

 pp. 596-597). The first published figures of Cephalodiscus, made from 

 drawings supplied by Prof. M'Intosh, appeared in E. K. Lankester's 

 article " Polvzoa "' in the ' Encvclop.iedia Britannica,' ed. 9, xix. 1885, 

 figs. 8-10. 



