DECAPOD CRUSTACEAliS OP THE OXFORD CLAY. 545 



chelae &c., are preserved, and constitute the only evidence available. 

 It therefore seems desirable, as affording a more complete knowledge 

 of the Crustacean fauna of the period, to record the occurrence of 

 these detached chelae rather than pass them over unnoticed. 



The Huntingdonshire • specimens which have come under my 

 observation I have ventured to refer to some 15 or 16 distinct 

 species. So far as I have been able to ascertain, none of these have 

 been described in any English publication, nor has their occurrence 

 in Britain been previously recorded, with the exception of one 

 species of Eryma {E. Babeaui) mentioned by Mr. Etheridge as having 

 been found in the Kimmeridge Clay. I am of opinion that seven 

 species can be identified as forms which have been described by 

 foreign palaeontologists, and seven I have been induced to regard as 

 new to science. 



The genus 



; Eryon 



is represented by 





1 species. 





Eryma 





5 



or 6 „ 





Glyplicea 







2 





Magila 





2 



or 3 „ 





Mecochirus 







1 





Goniochirus 







1 





Pseuda«tams ? 







1 





Pagurus ? 







1 



Eryon sublevis, nov. sp. (PI. XVI. fig. 1.) 



Carapace about one fifth wider than long, strongly arched 

 transversely ; interorbital portion of frontal border widely emar- 

 ginate, beaded by an edge of small tubercles (antero-lateral border 

 broken) ; that of the postero-lateral region gradually inclining 

 inwards posteriorly, and fringed by a series of acute, slender, 

 marginal spines. Cervical sulcus narrow, crossing the central 

 dorsal ridge about midway between the frontal and the posterior 

 border ; gastric regions rather intumescent. The surface of the 

 cephalic portion bears numerous, small, round tubercles, regular in 

 size, but irregular in disposition ; a strong lens renders visible 

 minute puncta between the tubercles ; similar but more scattered 

 tubercles occur on the outer portions of the scapular regions, but the 

 spaces between the central and the lateral branchial ridges are 

 smooth ; the metabranchial regions are strongly deflected laterally. 

 A strong, central, longitudinal ridge, crowded with tubercles, ex- 

 tends from thej)osterior border of the carapace, crosses the cervical 

 sulcus, but does not reach the frontal border ; and on each side 

 of it, about one fifth nearer to it than to the postero-lateral 

 border, is a similar, nearly straight, lateral, scapular ridge. These 

 lateral carinae interrupt the cervical sulcus, but are not distinctly 

 traceable in front of it (posterior border of carapace imperfect). 

 First pair of chelae of moderate size : basal portion of propodite (hand) 

 about half the length of the carapace, smooth ; fingers slender, 

 equal ; carpodite half as long as the hand. 



Compass-measurement. Carapace 2-| inches wide and 2 inches 



