84 
HAYDEN: GEOLOGY OF SPITI. 
Lima serraticosta, Bittner. 
Megalodon ladakhensis, Bittner. 
(?) Dicerocardium, sp. 
Spirigera n. sp. 
The quartzite series is overlain by a mass of dark grey, often dolo- 
Megalodon lime- tnitic, limestone, having a thickness of about 
2,300 feet. This must include representatives of 
the European Dachsteinkalk, lias and middle Jurassic. Fossils are very 
rare and badly preserved, but at 50 feet above the quartzite a band 
of grey limestone, about 20 feet thick, contains immense numbers of 
Megalodon ladakhensis, Bittner, and Dicerocardium himalayense, 
Stol. Where the rock has been polished by the action of running 
water or moving ice, it "has a most striking appearance, for the 
sections of the two bivalves, being preserved in white calcite, stand out 
clearly in fantastic patterns from the dark grey matrix (see PI. XV, 
fig. 1). This is the characteristic horizon of Stoliczka's " Par5 lime- 
stone," ^ blocks of which are very common throughout the upper 
Pdri valley between the Parang \A and Rupshu. 
Otlier fossiliferous ^bout 200 feet higher up the massive lime- 
horizons, stone has yielded one brachiopod and two 
bivalves, viz. — 
Spirigera noetlingi, Bittner ; 
Lima ctimaunica, Bittner; and 
Lima scraticosta, Bittner. 
In addition to these, gastropods and bivalves have been found at 
about 400 feet above the quartzite series, and 
a species of Spiriferina closely resembling 
S. obtusa, Oppel, about 400 feet higher still, while at about 370 
feet below the top of the limestone mass, Dr. von Krafft found an 
ammonite very nearly allied to, if not identical with, Stephanoceras 
coronatum, Brug. ; the horizon at which this fossil occurs may 
therefore represent the middle oolite, and since there is no trace of 
unconformity in this great limestone series anywhere in Spiti, the beds 
' Memoirs, G. S. I., vol. V, p. 124. 
( 84 ) 
