932 P. T. CLEVE, S. ATLANTIC PLANKTON. 



Coscinodiscus tumidiis Janisch (Exp. Gazelle PI. III f. 6. 

 A. S. Atl. LIX f. 38, 39). This form, nearly akin to C. U- 

 neatus, is characteristic of the antarctic regions. It was found 

 in many samples from 42° S. 3° W. to 44^ S. 48° E. 



Dactjliosolen antarcticus Castr. (Challeng. Rep. Diät. PI. 

 IX f. 7) was not rare in samples from 42' S. 3 W. to 44" S. 

 48= E. 



Dactjliosolen mediterran eus H. Per. More or less sparingly 

 in samples from 42° S. o W. to 45' S. 34 E. 



Euodia (Actinocjclns) gibba Bail. (in Pritch Inf. p. 852 PI. 

 VIII f. 22). Tlie diatom I consider to represent this species is 

 nearly akin to Coscinodiscus curvaüthis, liaving the puncta 

 arranged in the same manner and. besides, a pseudonodule; I am 

 therefore inclined to consider it as an asymmetrical variety of 

 the named Coscinodiscus. It may be possible that E. ventrieosa 

 Castr. (Ghali. Rep. Diät. PI. XII f. 5) represents this species, 

 but the figure is too had to admit of identitication. — This 

 form occurred sparingly in many samples from 41' S. 6° W. to 

 45° S. 34° E., besides at 41° S. 80° E. 



Fragilaria kerg-uelensis O'Meara \Terehraria kerguel. O'M. 

 Linn. Soc. J. Bot. XV p. 56 PI. 1 f. 4. — Fragilaria ant- 

 arctica ScHWARTZ Sitzungsb. d. ges. naturf. P'reunde zu Berlin 

 1877. F. antarctica Castr. Chall. Rep. Diät. PI. XXV f. 12. 

 1886. Fragilaria {an Terebraria?) Castr. 1. c. PI. XXV f. 1, 2. 

 — ■ Denticula antarctica Janisch Exped. Gazelle PI. III f. 1. 

 Fragil. Castr acatiei De Toni, Lemmermann, Abb. Nat. Ver. 

 Bremen. Vol. XVI PI. II f. 28, 29]. O'Meara's figure is erro- 

 neous, but can, to judge from the iocality and the characteristic 

 form of the figured coJony, scarcely represent another form than 

 this antarctic species. It was found in almost all samples from 

 41° S. 6° W. to 32 S. 91 E., most abundantly along 45° S. 



Navicula Trouipii Gl. N. Sp. Sectio Navicuke orthostichce 

 Valve thin, 7 times longer than broad, acute. Median line straight. 

 Gentral nodule very small, not transversely dilated. No areas. 

 Striae: coarser longitudinal, 20 in 0,01 m.m. and finer transverse, 



