BRITISH FOSSILS. 



Decade VII. Plate VIII. Fig. 1. 



EEMOPLEURIDES COLBII. 



[Genus EEMOPLEURIDES. Poetlock. (Sub-kingdom Articulata. Class Crus- 

 tacea. Order Entomostraca. Tribe Trilobitee or Palseadae.) Body attenuated bebind ; 

 glabella circular, occupying the greater part of the bead, with an abruptly produced 

 front ; its sides closely encircled by the very long smooth eyes ; eye line ending pos- 

 teriorly close to the axis ; cheeks small, produced into spines ; hypostome truncate in 

 front ; body segments 11, the 7th or 8th with appendages, the axis broad, the pleurae 

 falcate ; tail minute, the axis very short, of 2 or 3 segments, the border spinose [4 spined.] 

 Caphyra, Bakr. Amphitryon^ Corda.] 



[Sub-genus Remopleurides. Glabella furrows quite obsolete.] 



Diagnosis. R. longi-ovatm ; glabella maximdj quam longd latiori, ad 

 frontem inter oculos angustd ; genis parvis, in spinas breves divergentes 

 extensis ; thoracis axi latissimo, anterius fere pleuram ter superante ; 

 pleuris brevibus (^septimo haud producto ?) fulcro ad axin appresso, in 

 tuber culum longum valde protenso ; caudd siibquadratd, axi abbreviate 

 biannulatOf [margine quadrispinoso, spinis externis brevioribus.'] 



Synonyms. Remopleurides Colbii, Portlock (1843), Geol. Kept., 

 Tyrone, 256, pi. 1. fig. 1. R. Kolbii, Emmrich (1845), Neues Jahrb. 45. 

 M'COY (1846), Syn. Carb. Foss. Irel. 43. 



The fortunate discovery by Lieutenant-Colonel Portlock of three 

 or four species of this most remarkable group, enabled its discoverer 

 at once to establish it as a new genus, allied to Olenus and Para- 

 doxides, a relation borne out by many points of its structure. A 

 more perfect specimen, since found in Ireland by the Geological 

 Survey, enables us to supply some points left doubtful in his 

 descriptions, and we have figured afresh three of his original 

 specimens to illustrate a suggestion thrown out by him, that the 

 variations in proportion observable in these closely allied species 

 may be sexual rather than specific characters. New species have 

 been discovered both in Britain, Sweden, and Bohemia, but except 

 in these countries the genus is not yet known. 



[VII. viii.] 7 H 



