302 150 
marginal loculi, which are difficult to see, as this small form is very 
hyaline. The specimens in which I could not see the four pair of 
loculi otherwise agree in shape and structure with those where the 
loculi are visible. 
KKt, LN, TK, KCg—KSm (4 samples). 
208. M. rhombica Cl. Cl. Vega Exp. tab. XXXV, fig. 9. 
Found only in a sample from KCn. 
Area: Labuan. 
209. M. Smithi Thw. var. amphicephala Grun. A.S. Atl. tab. CLXXXV, 
figs. 13—14 = M. capitata Grev. Cnfr. Cl. Syn. Il, p. 152. 
KKm. 
Area: England, Baltic, Scotland, Morocco, Calcutta (M. capitata of Greville). 
210. M. parvula Ostr. n. sp. Tab. nostr. II, fig. 35. 
L. 0,021 mm., b. 0,009 mm. Striz 20 in 0,01 mm., loculi 5—6 
in 0,01 mm. Valve elliptical with short rostrate apices. Apical area 
narrow but present. - 
KKt (2 samples). 
This small species reminds somewhat of M. Smithi Thw. var. conifera 
Brun. (Perag. Diat. de Fr. tab. VI, fig. 41), but owing to the narrow central 
area it ought to be considered a separate species. 
911. M. sp. Tab. nostr. Il, fig. 36. Cnfr. A.S. Atl. tab. CLXXXVII, 
fig. 41. 
L. 0,061 mm., b. 0,02 mm. Strie 16—17 in 0,01 mm. towards 
the apices slightly curved, loculi 10—11 in 0,01 mm. Raphe slightly 
undulated, narrow transapical area. 
KKt (1 sample). 
The form figured by A.S. (from Baltschick) is referred to M. elegans 
Lewis in the description of plates, but the present form does not agree 
with any of the figures referred by Cl. Syn. Il, P.154 to Mast. elegans. 
912. M. sp. Tab. nostr. JI, fig. 32. 
L. 0,066 mm., b. 0,028 mm. Strize 8—9 in 0,01 mm., loculi 4 
in 0,01 mm.? 
Valve lanceolate with somewhat rostrate apices. Median line 
straight. Apical area very narrow. Strie composed of punctae 
forming decussate lines. Loculi difficult to see. In one specimen 
I have seen them near the apex, to which they reach. 
KKt, s.1. (2 samples). 
I think this species is nearest to M. asperula Grun. (Cl. Le Diat. I, 
tab. IX, fig. 12), but I have preferred not to state it as a separate species, 
as I have only seen specimens either without or with incomplete loculi- 
ferous rim. 
Area of M. asp.: Baleares, Seychelles, Java, Cebu. 
