58 PERMIAN FOSSILS. 
Class CRUSTACEA.! 
The microscopic Infusoria, as well as the grain-like Foraminifera and their allies, 
the comparatively massive Nummulites, have not only by their enormous local 
accumulations demanded the admiration of the student of geology, but by the wonders 
of their form and structure have called for the assiduous labour of some of the first 
naturalists of the day. The endless variety of these Microzoa, together with the little 
Coral-polyps and their congeners, have exercised the skill and excited the eloquence of 
collector and author ; there remains, however, a group of minute animals that have well 
performed their part in building up the rocks of this globe of ours, but which have met 
with little attention and less notoriety. Weallude to the Entomostracous Crustacea,—a 
group of considerable value in a paleontological point of view, and well entitled to 
rank amongst those minute organisms, whose rapid multiplication and frequent 
exuviations have, by local aggregation, given rise to, and are still producing, those 
astonishing lithological results, which, though passed over unnoticed by the many to 
whose comfort or even existence they are subservient, or to whose injury or incon- 
venience they tend, are viewed with careful earnest eye by the natural philosopher, 
tracing the most important results from apparently the meanest source. 
In 1793, the Rev. Dr. Ure, of Rutherglen, noticed the existence of certain ‘ micro- 
scopic bivalve shells” (Cytheres)in the Limestone near Glasgow, and collecting a sufficient 
quantity, supplied his friends with suites of the little fossils, and a tastily-mounted set 
in a glazed frame is still preserved in the Hunterian Museum. But it was not until 
twenty years afterwards that any fossil species of Entomostraca was recognised and 
described. 
M. Desmarest in 1813 figured and described his Cypris Faba from a tertiary 
fresh-water formation. Six years afterwards, this was followed by a notice of one or 
more of the Cyprides of the Wealden by Prof. Sedgwick. Another interval of five 
years, and M. Alex. Brongniart notices a tertiary species from France and Germany ; 
and other Wealden species are figured and described by Dr. Fitton and Mr. Sowerby. 
In 1826, M. Hisinger describes two species of Entomostraca from the Silurian rocks ; 
and four years afterwards, Count Minster describes fourteen tertiary species, and eight 
species from the Mountain-limestone. 
After this slow progress our knowledge of the fossil Entomostraca, or rather 
Ostracoda, advanced more rapidly. Mr. Lonsdale discovered Cythere in the English 
Chalk. M. Roemer added several species to Miinster’s list, figuring all the tertiary 
species of Germany, and in 1842 he figured and described seven species from the 
Chalk. Reuss, Koninck, Cornue!, Bosquet, Phillippi, Dunker, Hibbert, Horner, Phillips, 
Murchison, M‘Coy, Portlock, Sowerby, Bean, Morris, Williamson, &c., added other 
species from various sources; but as yet only two or three groups of sedimentary 
1 By Mr. T. Ruperr Jones. 
