TRANSLATIONS AND NOTICES 



GEOLOGICAL MEMOIRS. 



On the Silurian Crustacea, Pteropoda, and Cephalopoda 

 0/ Bohemia. By M. J. Barrande. 



[Leonhard u. Bronn's N. Jahrb. fiir Min. n. s. w. 1854, pp. 1-14.] 



In a letter to Professor Bronn, M. Barrande gives the following 

 interesting account of the subject-matter of the Second Part of his 

 great work on the Silurian Formation of Bohemia, on which he is 

 at present actively engaged. This forthcoming volume will treat of 

 the remainder of the Crustaceans, and the Molluscs belonging to the 

 Pteropod and Cephalopod Classes. 



Crustacea. — Already, as a supplement to the First Volume, says 

 M. Barrande, I have some new Trilobites, two species of which are 

 quite distinct from any yet described, — Ampyx gratus and Bronteus 

 Clementinus . The latter is distinguished by having as many long 

 spines as there are ribs on the pygidium. I have also materials for 

 completing the description of some of the as yet imperfectly known 

 species, as Trilohites mtUilus, Homalonotus Bohemicus, and others. 



The other crustacean fossils belong to families very diiFerent from 

 those of our existing seas. Firstly, some very imperfect remains, 

 which I refer to the genus Eurypterus ; and, secondly, fragments of 

 different species of Pterygotus, which have much resemblance to those 

 portions figured and described by Mr. Salter in the Quart. Journ. 

 Geol. Soc. vol. viii. p. 386. pi. xxi. Thirdly, of the forms which in a 

 former letter I referred to as Ceratiocaris=^Leptocheles* , M'Coy, I 

 distinguish three species, and am acquainted with the whole animal, — 

 its two flaps and the tripartite caudal extremity (Jahrb. 1853, p. 342). 

 This animal, which I have noticed as occurring in France, the United 

 States, and in England, appears likely to be a characteristic fossil 

 of the Third Silurian Fauna. 



Fourthly, the family of Cytherinidce has already supplied me 

 with upwards of 30 species, with individuals from 2 to GO and 80 



[* Thus given in the original. The genera Ceratiocaris and Leptocheles are 

 very distinct, according to Prof. M'Coy's descriptions and figures. Dithyrocaris 

 may probably include the forms alluded to. See also Prof. J. Hall's Palaeont. New 

 York, vol. ii. pi. 71. — Transi..] 



VOL. X. PART II. C 



