151 303 
Gomphoneminae. 
Rhoicosphenia Grun. 
213. R. tenuissima Ostr. n. sp. Tab. nostr. Il, fig. 28. 
L. 0,02—0,03 mm., b.0,002 mm. Striz at least 25 in 0,01 mm. 
Valve clavate. In the middle a structureless area seems to be 
present, which with lower enlargement resembles a stauros. In 
epitheca the strie are conspicuous, but in hypotheca I have not 
been able to see any striation. 
KKt (1 sample). 
This small species is exceedingly delicate and hyaline and therefore 
it is easily overlooked. 
Cymbellinae. 
Amphora Ehb. 
214. Amphora acuta Greg. Perag. Diat de Fr. tab. XLIX, fig. 26. 
Found only in a sample from K Kt. 
Area: Arctic Ocean, Europe. Mediterranean, Morocco, Cape Horn, Magel- 
han’s Strait, Ceylon, China. 
— — var. areuata A.S. Perag. 1. ¢.,: fig. 28. 
KKm, KKt, KMn—CLt (8 samples). 
Area: Gulf of Mexico, Mediterranean, Seychelles, Macassar, Mazatlan, 
Samoa. 
215. A. angusta (Greg.) Cl. Perag. Diat. de Fr. tab. L, fig. 37. 
K Kt (7 samples). 
Area: Arctic Ocean, Europe, America. 
— — var. ventricosa Greg. Perag. l.c. fig. 39. 
K Kt (2 samples). 
Area: Arctic Ocean, Europe, Bab el Mandeb, Monterey. 
216. A. bigibba Grun. A.S. Atl. tab. XXV, figs.66 and 74—76. 
KKt, KMn—CLt (6 samples). 
Area: the coasts of America, Baleares, Adria, Cape of good Hope, Japan, 
Celebes, Ceylon, Java, Galapagos. 
217. A. costata W.Sm. A.S. Atl. tab. XXV, fig. 30. . 
Found only in a sample from K Kt. 
Area: New Haven, Pensacola, Colon, Porto Seguro, Campeachy Bay, North 
Sea, Mediterranean, Adriatic, Galapagos. 
