BRITISH FOSSILS. 



Decade VII. Plate X. Figs. 1 to 7. 



^GLINA MIRABILIS. 



[Genus JEGLINA. Barrande. (Sub-kingdom Articulata. Class Crustacea. Order 

 Entomostraca. Tribe Trilobitae or Palseadse.) Body oblong, the extremities equal, 

 rounded ; head convex, glabella large, parabolic, not distinctly lobed ; eyes very large, 

 occupying the whole or nearly the whole cheek, coarsely granulated (externally ?) ; facial 

 suture ending on the posterior margin close to the axis, no rostral shield ; thorax with 5 

 or 6 rings, the axis broad, the pleurae facetted and grooved ; tail large, the axis of 2 or 3 

 rings, abbreviated ; the sides few-ribbed, or nearly smooth. Cyclopyge, Corda.] 



Diagnosis, j^. capite gibbo, glabella parabolicd longdyfrontem imperii 

 dente, et retrorsum lobum cervicalem fere excludente ; oculis maximis, totam 

 genam occupantibuSy et sub margine glabellcB frontali connatis. 



Mglina mirabilis, Forbes, MSS. 



Of all trilobites with eyes, this has the largest and most con- 

 spicuous ones, for they cover not only a large part, but the entire 

 side of the head, leaving scarcely a margin. All the species, and 

 there are four or five described, are furnished with these dispro- 

 portionate organs of vision, but in that which forms the subject of 

 our plate they are more largely developed than in any other, for the 

 two eyes meet in front of the glabella, dividing that portion alto- 

 gether from the front margin, and occupying therefore the whole 

 length of the facial suture. 



The genus was first sufficiently described in M. Barrande's 

 " Notice Pr^liminaire sur le Systeme Silurien de Boheme," and is 

 much more frilly treated of in his lately published work. Previous to 

 his visit to England, the group was supposed to be a new one ; but 

 he kindly showed us in his unpublished figures several forms of 

 this remarkable group, none, however, in which the development of 

 the eyes is carried to such an extravagant degree as in the British 

 species. It is thought better, therefore, to figure so conspicuous a 



[VII. X.] 7 K 



