( 1129 ) 
regularly laterally interlocked, more or less vertical thickenings of 
the parietes are formed slightly diverging from the centre, which 
are imperfectly developed skeleton-columns. On either side of the 
median plane are in the centrum about 20, at the periphery only 
5 strata of median ventricles. 
In a dense, grey limestone, which is found half way to the top of 
the range of mountains containing the spring of the Sepaku, I found 
many Orbitoides, showing in the main great resemblance to those 
just deseribed. The shape of the median chambers, the structure of 
their parietes, their dimensions and likewise the shape and situation 
of the lateral chambers are ccmpletely alike. The largest diameter 
is 23 mm. Only the shape of the embryonal chamber, which like 
the second chamber is very large, shows a great difference. Both 
these chambers communicate with each other by a very wide opening. 
The two described Orbitoides consequently form a distinct pair: 
the fossils of the Pamaluan are the microspheric, those of the Sepaku 
the megalospherie forms. 
There are only very slight differences between tbe described form 
and ©. formosa. The inferior and rare, saddle-shaped bend of our 
Orbitoides is of little importance, it is well-known that in this respect 
many sorts, are very variable. SCHLUMBERGER (lI. ¢.) however reports 
about O. formosa, when describing the lateral chambers, that these 
are: “très surbaissées et séparées par de tres minces parois’, whilst 
in our form the horizontal parietes between the lateral ventricles are 
very thick. S. communicates too little about the shape of the median 
chambers to enable us to discover eventual differences with our form. 
In the lime-rock of the Sepaku-spring-mountains occurs another 
little Lepidocyclina that cannot be more exactly determined, besides 
the Orbitoid described; further Globigerina, and most likely Textu- 
laria. The limestone is grey and rather transparent on the section; 
it contains here and there microscopic grains of pyrite, which often 
fill the ventricles of Orbitoides. 
In the marl of the Sungei Pamaluan a few more smaller Lepido- 
eyclina were found (5 specimens) whose diameter was only 5 mm., 
in one case even less. The median chambers are rhombic on the 
horizontal section, most likely the embryonal chamber is small. The 
skeleton-columns at the surface have the appearance of small warts, 
the situation and number of which vary strongly even in this insig- 
nificant material. In two specimens there was only one central wart, 
two others showed many warts scattered all over the disk, whilst in 
the last specimen only a few warts lie round the centre. In general 
these characteristics agree very well with what is known of QO. neo- 
