On the Palceozoic Bivalved Enlomostraca. 339 



XLII. — Notes on the Palceozoic Bivalved Entomostraca. — 

 No. XVII. Some North- American Leperditife and allied 

 Forms^. By Prof. T. Rupert Jones, F.R.S., F.G.S. 



Having lately had an opportunity of examining the Silurian 

 Leperditice in the Museum of the McGill University (the 

 Peter-Redpath Museum), Montreal, and the American Museum 

 of Natural History at New York, I was enabled to make 

 some notes and sketches, and to secui'e some specimens from 

 typical localities, through the kindness of Sir William 

 Dawson and Prof. R. P. Wiiitfield, res])ectively. In ray 

 endeavour to determine the species which I then saw I have 

 been led to review nearly all that has been done in the eluci- 

 dation of these Silurian Bivalved Entomostraca, namely, the 

 Leperditice^ Isochilince^ and Primitive ; and, although I do not 

 presume that the work is as yet nearly accomplished, I ven- 

 ture to offer some of the results of the examination, as they 

 may be of use to other workers among the same and similar 

 fossils. 



It seems to me that the simplest plan will be to take note 

 of the genera and species as they occurred to me in the Museum 

 of the McGill University, especially as thereby many of our 

 Canadian friends will the more readily be able to refer to 

 several of the typical forms without trouble. 



Genus LEPEEDiTiAt, Renault. 



Leperditia, Rouault, 1851, Bullet. Soc. Geol. France, st5r. 2, vol. viii. 

 p. 377 ; Jones, 1856, Ann. cfe Mag. Nat. Hist. ser. 2, vol. xvii. p. 84; 

 1870, Monthly Microsc. Journ. vol. iv. pp. 188-190 ; Ann. & Mag. 



* For No. XIV. see Ann. &Mag. Nat. Hist. ser. o, 1881, vol. viii. p. .332; 

 and Supplemental Letter, ibid. vol. ix. p. 168 ; No. XV. ibid. 1882, vol. x. 

 p. 358 ; No. XVI. ibid. 1883, xii. p. 243. No. XIII. treated of the 

 Devonian Entnmides, in September 1879, and No. XII. of the Carboniferous 

 Carbonia;, iu July 1879. Some confusion iu the numbers inadvertently 

 occurred at pp. 332 and 168. 



t Tliis word has been a puzzle to the author of ' The American Palaa- 

 ozoic Fossils : a Catalogue of the Genera and Species,' &c., 8vo, Cin- 

 cinnati, 1877 ; for at p. 219 it is given as having been derived from 

 " lepis, a scale ; dittos., double '" ! ! M. Rouault definitely states that it 

 was named after a distinguished fellow-countryman, Dean of the Guild 

 of Tailors at Rennes, and chief magistrate there, in the troublous times 

 of 1794-5, and noted for his high character, his ability, and uprightness. 



Mous. P. Lebescoute, of Rennes, favours me with the following note : — 

 " Jean Leperdit, n^ a Kergrisel pres Pontivy le 5 mai, 1752, est mort a 

 Rennes en aoiit 1823. II exer^ait a Rennes la profession de tailleur lors 

 qu'eclata la revolution. II fut norame maire de Rennes pendant la Ter- 

 reur ; grace a sa courageuse energie, il sut tenir tete au farouche et san- 

 guinaire proconsul Carrier, et saiiva de I'echafaud un grand nombre d« 

 ses concitoyens. II mourut pauvre comme il avait vecu." 



