340 DISCOVERY REPORTS 



Entopyla kerguelensis Karsten. 



Karsten, 1905, p. 125, pi. 17, fig. 15. 



Cells large, often united to form short chains, but may be solitary. Valves dissimilar, 

 somewhat linear in outline, with weakly inflated apices, and a weak median constriction. 

 Apices slightly produced, obtusely rounded. The inferior valve is concave and possesses 

 prominent terminal nodules, nodules broadly oval. The superior valve is convex, and 

 without the terminal nodules, but the apices are very slightly recurved. The valve sur- 

 face is furnished with strong costae arranged on either side of a median line ; costae not 

 continuously transverse, but slightly divergent in the apical areas and almost parallel 

 in the median area of the valve. Connective zone well developed, showing numerous 

 internal septa. Chromatophores : numerous cocciform bodies. Apical axis of cell 

 120-136/x, transapical axis 38/i (median area). 



Observed at Sts. WS 481 ; MS 97. 



Suborder MONORAPHIDINEAE 



Family ACHNANTHACEAE 



Subfamily ACHNANTHOIDEAE 



I. Cells isobilateral upon apical axis only ... ... ... ... ... ... Achnanthes 



Subfamily COCCONEIOIDEAE 

 1. Cells isobilateral upon apical and transapical axis ... ... ... ... Cocconeis 



Subfamily ACHNANTHOIDEAE 



Genus Achnanthes Bory 

 Bory, 1822 a, p. 79 



Achnanthes kerguelensis Castracane. 

 Castracane, 1886, p. 41, pi. 20, fig. 15. 



Cells often united to form chains. Valves dissimilar. In outline the valves are lanceo- 

 late-rhomboidal with apices slightly produced, but obtusely rounded. The upper valve 

 bears a median raphe, the central hyaline space is extended laterally to form a complete 

 stauros. The lower valve possesses a pseudoraphe only, in the apical axis, and no trans- 

 apical stauros. Both valves are furnished with fine moniliform striae, arranged in 

 parallel transapical lines. Apical axis of cell 36^; transapical axis 16/x. Type locality, 

 near Kerguelen Island. 



A small stipitate epiphytic diatom characteristic of the coastal flora of the Antarctic 

 land-masses. Observed in small numbers only. 



Observed at St. WS 481. 



