Palceozoic Bivalved Entomostraca. 393 



begun, New South Wales, and are now in the British Museum 

 (Natural History) . 



These are internal casts, in a brownish fine-grained sandy 

 mudstone, and are associated with numerous ferruginous casts 

 and impressions of Trilobites (broken) and Brachiopods, such 

 as Cyhele, Proetus^ and Cyphaspis] Orthis^ 8tropliomena^ &c. 

 Besides several individuals of the Entomisy variously modified 

 by pressure (figs. 5, 6, and 7), there is a cast (internal) of 

 another Entomostracan form (fig. 17), the outline of which is 

 much like that of a Halocy^jris or a Conchoecia. Provision- 

 ally, however, I refer it to the Cypridinidae. 



Prof. Dr. L. de Koninck *, of Liege, has recognized in 

 some olive-coloured argillaceous rock from the same locality 

 (Yarralumla) specimens of apparently the same Entomis as 

 that above mentioned, together with numerous fragments of 

 Trilobites ( Galymene^ Cheirurus, Gronius, Encrmuncs^Proetus) , 

 and a branch of ^ Iveolites repens. 



M. de Koninck refers the species to M. Barrande's Entomis 

 pelagica, Syst. Sil. Boheme, vol. i. Suppl. 1872, p. 515, 

 pi. xxiv. figs. 1-6, which show the unaltered valves, with 

 their shape and profile well preserved, from the Upper-Silu- 

 rian stage, F f 2, at Konieprus, Bohemia. The size of these 

 is, for the largest specimens, about 6 millim. long and about 

 3 millim. in width. The test is smooth and yqxj thin. M. 

 de Koninck adopts M. Barrande's description of the valves 

 in great part, but does not mention whether his specimens 

 were in the state of casts or not. 



It is extremely probable, if not certain, that E. pdagica 

 and E. tiiberosa are synonymous ; and I would readily adopt 

 M. Barrande's appellation if the priority of the other did not 

 hinder me. The great extension of this old creature's habitat, 

 where now Scotland, Shropshire, Stafibrdshire, Bohemia, and 

 New South Wales severally exist, is very remarkable, and 

 indicates its truly pelagic nature. 



* " Reclierches sur les fossiles paleozoiques de la Nouvelle-CTalles du 

 Slid (Australie)." Exti-ait des ' Memoires de la Societe royale des 

 Sciences de Liege,' 2" serie, vol. \i. 1876, p. 45. 



At page 347 of the same work M. L. de Kouiuck notices a small Car- 

 boniferous Entomostracan, which he terms Entomis Jonesi ; but from 

 the drawings, figs. 6, 6 «, (36, pi. xxiv., this seems to me to be more like 

 M'Coy's L'ei/ricliia (?) hituhercuJata, having two equal lobes distinctly 

 divided by a broad transverse valley. A few individuals were found 

 associated with a little crowd of Polycope simplex, J. & K., in tiie sand- 

 stone of Muree, N. S. W. 



