(1123-4 
the declivity of the mountain-range where is the source of the 
Sungei Sepaku, which is as old as the strata on the Sungei Pama- 
luan ; Orbitoides were likewise found in marl in Pulu Balan, on 
the Sungei Binuwang, and in the delta of the Sungei Pamaluan, but 
these were not distinct enough to allow a specific determination. 
As all Orbitoides found belong to the subgenus Lepidocyclina and 
to the still younger, new subgenus Lepidosemicyclina, all strata are of 
a posteocene age '). | 
A very great number of sorts of Lepidocyclina of the Indian 
Archipelago has already been described ; I shall try to group these 
species in such a way as to give an easy survey of them, I am 
however quite aware of the fact that most likely | shall not fully 
succeed in this respect, on account of insufficient knowledge of the 
literature and inaccessibility of a great number of publications which, 
though not directly relating to the Indian forms, are nevertheless of 
great importance for the knowledge of Orbitoides. 
_ Among the Lepidocyclina known in India some are easily distin- 
guished because they are not round but star-shaped and even poly- 
gonal ; one form is characterized by the appearance of several strata 
of median chambers, whilst both, the very large and the very small 
ones, can bé easily separated from the others. The greatest difficulties 
offer the species with normal forms and average sizes. 
If in this communication numbers are given about the dimen- 
sions of Orbitoides d always means the horizontal diameter, / the 
height (thickness). 
1. Species of polygonal or radial form. To these belong O. radiata 
Martin?) O. Martint SCHLUMBERGER *), both of Java and perhaps 
O. murrayana Jones and CuapmMan *), of Christmas Island. O. radiata 
has an undulated circumference, the diameter is 8 m.m., O. Martini is 
purely star-shaped, the maximum-diameter is 6 m.m., O. murravana, 
of which only a horizontal section is known, is quadrangular ; d is 
9,375 m.m. Dovvirré has however rightly pointed out *) that the 
latter form is perhaps not star-shaped or polygonal at all, but round 
and bent strongly saddle-shaped, so that the horizontal section must 
obtain a polygonal or star-shaped figure. 
) K. Martin, Samml. d. Geol. Reichsmuseums of Leiden, 6. p.132—245, 1902. 
2) K. Martin, Die Tertiärschichten auf Java. 1880. 
) C. SCHLUMBERGER, Samml d. Geol. Reichsmuseums in Leiden, 6, p. 128—134. 1901. 
4) T. Repert Jones and F. Cuapmam, On the Foraminifera of the Orbitoidal 
Limestone and Reef Rocks of Christmas Island, in: C. Anprews, A Monograph 
Christmas Island, 1900, p. 226—264. 
5) H. Douvitté, Bull. Soc. Géol. de France (4) 5, p. 435—465. 1905. 
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