6g 



Diam. of valves, 0183 m.m. 



Area : length, 01 36 ; breadth, 01 13 m.m. 



Total length of rays from margin, 0,0299 m.m. 



Length of the punctate striae on each side, 0-026 m.m. 



Breadth of interruption of radial, 0003 m.m. 



Valves circular ; area quadrate. Number of double beads in 

 R. about 8 to 10. Str. with 10 puncta in each of the longer ones. 

 Centre occupied by a wide, blank space, on each side of which 

 are the punctate striae, followed by an external smooth space. No 

 circlet. A continuous line of small marginal beads. Rays at 

 interrupted portion, which occurs between the second and third 

 double bead, indicated by a fine line. Granules in the Rays 

 forming a double series. 



This diatom is from Hong-Kong. A smaller var., with central 

 portion of area clepsydrate, is from Derbend, in the collection of 

 Mr. Grove (slide 236). I call this C. Hardmanianus^ var. Grovii. 

 This diatom is probably a form of the much commoner C. 

 dtzmelianus, Grun. The original specimen named by Greville is 

 in my collection. 



Campylodiscus Kerguelensis. Deby. (PI. XV., f. 79.) 



Group of the Punctatae. 



Diam. of valves, o'oSo m.m. 



Area circular, diam. 0*053 m.m. 



Length of rays, o - oo8 m.m. 



Breadth of inter-radials, 0-003 na.m. 



A circlet formed by short, paired lines, one for each ray, and 

 one for each inter-radial. The circlet lines are faintly prolonged as 

 tine striae towards the centre of the area, needing good definition 

 to be well seen. Rays from 40 to 64 in specimens seen by me. 

 Area irregularly and indistinctly punctate. 



This diatom is from Kergueland's land, from Mr. Weissflog's 

 collection. Very rare. 



Campylodiscus Challengerensis. Deby. 



Group of Hyalinae. 



