6 



BRITISH FOSSILS. 



Remarks on the Genus^ 



When originally described by Beyricb, in 1845, he naturally included in this genus the 

 species of Cheirurus with an inflated glabella, in which the anterior furrows are nearly 

 obsolete, such as C. sphcericus of Esmark (which Sars described and figured as the 

 C. clavifrons, Dalm.), and the true C. clavifrons, of which Loven has since given so 

 excellent a description. But the latter species has the nodular and furrowed thorax rings, 

 spinose cheeks, and the long spined tail, characteristic of Cheirurus, so much so, that 

 Dr. Beyrich asserts that portions of separate trilobites must have been combined in the 

 description. We have, however, in England, as above described under Plate 2, the same 

 or a very closely allied species, showing these characters, which we formerly described as 

 Spkcerexochus, but now consider a true Cheirurus. The Cheirurus globosus of Barrande, 

 and the C. (Actinopeltis) Caroli Alexandri of Corda, are examples of this section, to which 

 for convenience sake, the sub-generic term Actinopeltis might be applied. [See Cheirurus^ 

 ante.] 



J. W. Salter. 



August, 1853. 



