Paleozoic Bivalved Entomostraca. 247 
p- 220, pl. ix. fig. 17), to which otherwise it has a strong 
likeness. 
Unfortunately even the concentric ridges are only imper- 
fectly preserved, and no interstitial ornament is at all visible 
on the mere film remaining where the valve was imbedded. 
Being inclined to regard it as a variety of the widely dis- 
tributed L. striata, I propose to distinguish it as var. tenue- 
pectoralis. 
Prof. Karpinsky labelled it as follows :—“ No. 3. Estheria, 
sp. Exemplaire unique trouvé prés de l’usine Kamensk 
(Oural, versant oriental) dans les couches carboniféres infé- 
rieures contenant de la houille.” 
Imperfect as these foregoing determinations of East-Uralian 
fossil Hntomostraca are in some respects, still the recognition 
of so many forms closely allied to species well known in 
Western Europe is of considerable interest to geologists and 
biologists ; and our thanks are due to our fellow-worker at 
St. Petersburg, Prof. A. Karpinsky, for the opportunity of 
comparing these rare Russian specimens with those which 
we know so well in Germany, France, and England. 
Il. Some Paleozoie Bivalved Entomostraca from Spitz- 
bergen. (Pl. IX.) 
In the winter of 1882-3 my friend Dr. Gustav Lindstrém 
wrote to me from Stockholm, stating that Dr. Nathorst had 
recently returned from Spitzbergen with a rich harvest of 
fossils, and that amongst them he had brought home what 
the paleontologists at Stockholm recognized as 
1. Leperditae in argillaceous schist of Devonian age 
from Klaas Billen Bay. Some small fragments of placoderma- 
tous fish-remains are also present. 
2. Hstherie in a dark-coloured, micaceous, and carbonace- 
ous shale (labelled ‘‘ Mimers dal” and ‘“‘ Mimers dal mid- 
ten”) ; the greater part thinly laminated, with black Estherian 
films crowded on the planes of bedding; and some pieces 
more solid, rather lighter in colour. In these latter, which 
are chiefly marked “ Mimers dal midten,” an occasional hard 
carbonaceous nodule (coprolite) appears. 
3. Accompanying the above there was a specimen of reddish 
limestone (waterworn), labelled “ Liebde Bay, North-polar 
Expedition, 1868,” which contains numerous Leperditic, 
1. The Leperditice in the soft schist, or schistose mudstone, 
from Klaas Billen Bay are very numerous (see Pl, IX. 
figs. 1-8). They are all casts and impressions in the schist, 
lying at various angles to the original bedding, ben crumpled 
* 
