54 HAYDEN : GEOLOGY OF SPITI. 
By the employment of the term " Productus shales," restricted as 
above, the confusion that has hitherto prevailed with regard to the 
"Ruling series" will be avoided, for Stoliczka included in that 
series the beds lying between the Muth quartzite and the triassic 
limestone, and it should consequently embrace the whole of the 
carboniferous limestone of Lio in Kanaur, as well as the overlying 
shales and quartzites of lower Spiti, and since the shales of the 
Po series are often lithologically indistinguishable from the " Produc- 
tus shales," the retention of Stoliczka's nomenclature would inevi- 
tably lead to confusion. 
Throughout Spiti and Bashahr the Productus shales are highly 
fossiliferous, more especially in the lower part 
Fossils. ... 
of the series, where numerous brachiopods 
occur^ both in the shale and in the sandstone partings. Although 
individuals are numerous, only a few species are represented ; these 
include — 
Marginifera himalayensis, Diener. 
Spirifer rajah, Salter. 
„ fasciger, Keyserling. 
Chonetes lissarensis, Diener. 
Productus cf. gangeticus, Diener. 
Spirigera gcrardi, Diener. 
Numerous concretions occur, both isolated and in bands, through- 
Horizon of Xenas- out the shale, but they rarely contain fossils. 
pis and Cyclolobus. In the upper part of the bed, however, about 
30 feet below the top, is a band of concretions containing Ammonoidea, 
which consist chiefly of Xenaspis cf. carbonaria, Waagen, and 
Cyclolobus cf. oldhami, Waagen.^ 
In addition to the above fossils, a few Bryozoa and badly pre- 
served plants have been found. 
* The collections which have now been described by Professor Diener, com- 
prise several new species, including — 
Cyclolobus insignis. 
„ [Krafftocerai) kraffti. 
„ ( „ ) haydeni, 
( 54 ) 
