48 
HAYDEN: GEOLOGY OF SPITI. 
It is highly probable, therefore, that the lower part of the shale and 
quartzite series is liomotaxial with the Culm, while it is particularly 
interesting to note that the only form which has been identified with 
any certainty belongs to an Australian species. The presence of Culm 
beds overlying the limestones of the Lipak river is a further proof, if 
such were needed, that the latter should be referred to the lower, 
and not to the upper, carboniferous. 
Two other horizons are seen in the ridge north-east of Po, a few 
Shale with concre- hundred feet above the path to Thabo. The 
lower horizon is a. black shale with concretions, 
which frequently contain well-preserved fossils, chiefly Brachiopoda. 
The shales in this locality are everywhere full of concretions, but 
although many hundreds of these have been broken open, they 
have been found to contain fossils at only this one horizon, which 
consists of two rows of concretions separated from one another by 
about two feet of shale ; in the lower row, fossils are rare and consist 
chiefly of species of Nautilus, while the upper band contains Brachio- 
poda and Bryozoa. 
The small collection of fossils obtained from this horizon com- 
prises the following forms : — 
Productiis scabricitlus, Martin. 
'„ lineatus, Waagen. 
Dielasma, sp. 
Spirigera sp. cf. gerardi, Diener. 
Reticiilaria lineata, Mart. 
Spirifer cf. triangularis, Mart. 
Nautilus sp. 
Orthoceras sp. ' 
Pleurotomaria sp. 
Fenestella sp. 
rigida Ludv\ ig de la m^me formation, mais qui sont encore moins susceptibles d'une 
determination certaine. 
En resume, il est difficile de tirer de ces materiaux une conclusion tout k fait 
sure en ce qui toncerne I'age des couches dont lis proviennent : cependant I'identite 
de la Fougere la plus abondamment representee avec le Rhacopteris incequilatera 
du Culm de la Nouvelle-Galles du Sud me parait assez probable pour me donner 
lieu de penser que ces couches doivent appartenir a peu pres au mfeme niveau 
que celles d'Arowa et Port Stephens." 
( 48 ) 
