PERNIIA^ SYS+EM. 53 
Throughout Spiti and Bashahr the calcareous sandstone is invari- 
„ , . ably overlain by a bed, usually from 100 (o i >;o 
Productus shales. . . . 
feet thick, of black or dark brown, often siliceous, 
shale, M'ith a few thin bands of bard, brown concretionary sandstone 
near its base. This bed constitutes the " Productus shales," which 
extend, with little variation, throughout the entire length of the 
Himalayas from the Nepdl frontier to Kashmir. 
When first noticed by Stoliczka in Spiti, these shales were named 
the " Kuling shales," from the village of Kuling, on the Pin river, 
where they are well exposed and highly fossiliferous. Stoliczka's 
nomenclature was adopted by Lydekker in Kashmir, but the term was 
subsequently rejected by Mr. Griesbach, wl.o substituted the name Pro- 
ductus shales," and since this term has now been so generally adopted 
and, owing to the large number of Producti always found in the shales, 
is particularly appropriate, it has also been employed in the present 
memoir, but Stoliczka's original section at Kuling may still be retained 
as the type for this part of the Himalayas. 
An excellent section is seen on the small ridge behind the village, 
where the calcareous sandstone (Stoliczka's ' quartzite ") is overlain 
by about 150 feet of dark shale, with a few irregular sandstone part- 
ings. Above the watercourse which supplies the village, the shales, 
dipping into the hill, form a steep slope and, near the base of a 
small cliff which caps the ridge, are overlain by a narrow band of hard 
ferruginous limestone succeeded by thin alternating beds of shale and 
limestone ; the ferruginous limestone includes Griesbach's " Otoceras 
beds," which were regarded by him as either of lower triassic age or as 
permo-trias passage-beds. The underlying shales constitute Stoliczka's 
**Kulin[j shales," for which the term "Productus shales" is now 
substituted. 
The limits of this bed are everywhere clearly marked, and the 
"Productus shales" of Spiti and Bashahr may be defined as a band 
of dark shale with irregular sandstone partings, included between 
the top of the fossiliferous calcareous sandstone and the ferruginous 
limestone containing the zone of Otoceras woodwardi, Griesbach. 
( 53 ) 
