342 DISCOVERY REPORTS 



spent on the feeding grounds before returning to warmer waters to breed, and he ob- 

 tained confirmation of Bennett's observations (Bennett, 1920, p. 353) that whales with 

 a heavy diatom infection are fatter and altogether in a better condition than those not 

 infected . 



Cocconeis imperatrix A. Schmidt. (PI. X, figs. 8, 9.) 

 A. Schmidt, 1894, pi. 189, figs. 11-15. 



Cells broadly oval, often large, valves flat, dissimilar. The upper valve is very ornate. 

 The fine raphe is surrounded by a very narrow hyaline area and the broad central area is 

 furnished with furrows containing two lines of puncta arranged transapically. The lines 

 of puncta are almost parallel, straight in the median portion, curved towards the apices. 

 The furrows are interrupted by a narrow hyaline ridge which follows the line of the 

 margin of the valve a short distance inside it, but they are continued again between it 

 and the valve margin, forming a number of elongated marginal loculi. The lower valve 

 possesses a pseudoraphe which is somewhat fusiform, and the furrows on the valve 

 surface, which are a little less distinct than those on the upper valve, proceed towards 

 the margin of the valve and are not crossed by the hyaline ridge. Apical axis of cell 

 80-1 50/x. Type locality, Magellan Straits. 



This species is a common littoral diatom in the South Atlantic, and was observed in 

 the Bransfield Strait and in East Cumberland Bay, South Georgia. 



Observed at Sts. 552; WS 481 ; MS 97. 



Cocconeis pinnata Gregory ex Greville. 



Greville, 1859 a, p. 79, pi. 6, fig. 1. 



Cocconeis pinnata var. plena M. Peragallo, 1921, p. 53, pi. 2, fig. 4. 



Cells small, valves oval, raphe distinct. Valve surface covered with strong moniliform 

 striae. Striae slightly curved about the apices. Axial area narrow, linear to linear- 

 lanceolate. Apical axis of cell 40/x ; transapical axis 28/x. 



I have united Peragallo's C. pinnata var. plena with the type. As far as I can ascertain 

 the features upon which Peragallo established the variety are in themselves of no im- 

 portance and vary considerably from specimen to specimen. 



Observed at Sts. 664; WS 481 ; MS 97. 



Cocconeis scutellum Ehrenberg. 



Ehrenberg, 1838, p. 194, pi. 14, fig. 8. 

 Hustedt, 1930, p. 191, fig- 267. 



Cells small, usually solitary. Valves oval in outline, valve surface flat or nearly so. 

 Valves dissimilar. The one bears a narrow and short, straight raphe surrounded by a 

 narrow axial area, and furnished with radiating lines of small puncta which terminate 

 in a small cluster of puncta a short distance from the valve margin. The punctate por- 

 tion is surrounded by a narrow but distinct hyaline marginal band. The other bears a 

 narrow pseudoraphe and is furnished with coarser puncta than those upon the raphe- 

 bearing valve, arranged in weakly radiating lines on either side of the narrow axial area. 



