296 144 
165. N. (Trachyn.) velata A.S. A.S.. Atl. tab, XLVIII, fig. 36. 
KKm, KKt, KMn—CLt (7 samples). 
Area: Cape Horn, Cape of good Hope, Madagascar, Mauritius, Ceylon, 
King Georges Sound, Sumatra, Java, China, Japan, Sandwich Islands, New 
Caledonia. 
In a sample from KCgN I have found a Nav. (Trachyneis) exactly 
corresponding to the ,fragliche Form‘ from North Celebes figured by 
A.S. in Atl, tab. XLVI, fig. 31. 
Cymatoneis Cl. 
166. (©. suleata Grev. A.S. Atl. tab. CCXII, fig. 44. 
Found only in a sample from K Kt. 
Area: Widely spread in warmer Seas. 
Van Heurckia Bréb. 
167. V. H. siamensis Ostr. n. sp. Tab. nostr. Il, fig. 26. 
L. 0,074 mm... b. 0,009 mm. 
Valve linear elliptical with rounded apices. Raphe strongly 
asymmetric, enclosed between two silicious ribs, terminating in a 
outwards reflexed point. Strie very fine, parallel. I am not able 
to see any longitudinal striation. 
KKm, TK (2 samples). 
This species surely is near to Van Heurckia vulgaris Thw. var. 
asymmetrica Cl. (Cl. Syn. I, p. 122, tab. V, fig. 29), but as it is char- 
acteristic by its shape, the very asymmetrical raphe and the exceedingly fine 
sculpture, I preferred to regard it as a separate species. 
Area of V. H. vulg. var. asymmetrica Cl., which is recorded as ,brackish*: 
Sierra Leone, Gameroon, Tasmania, Newark, N. Yers. fossil (Champlain epoch). 
168. N. subglabra Ostr. n. sp. Tab. nostr. Il, figs. 23 & 24. 
L. 0,059 mm., b. 0,016 mm. (fig. 23). L. 0,056 mm., b. 0,013 mm. 
(fig. 24). Strize inconspicuous. Valve rhombic-lanceolate. Central 
pores distant, terminal nodi distant from the apices. 
With Zeiss Apoch. no. 2 and oblique illumination I think 1 have 
seen a striation at a right angle to the apical axis; with moderate power 
the valve gets a chagreen-like appearance. In its central part the valve 
shows like a tendence to a cicatrice-like figure, which is very conspicuous 
in other specimens, as I have figured it in my fig. 24. The latter form is 
somewhat smaller but otherwise on the whole agreeing with the former, 
so that I have no doubt that they belong to the same species, perhaps as 
hypotheca and epitheca. Moreover they occur both in the same sample 
— from TK — and only in this. 
I am uncertain as to the systematic position of this species. 
