BRITISH FOSSILS. 



7 



likely that both British and foreign naturalists should conceive the 

 common Dudley species, with a pointed front, to represent the more 

 pointed variety of Brongniart. Green, in his description of the 

 G. macTophthalma, 1832, noticed the great difference between the 

 two figures : and, referring to a fine slab of Dudley trilobites, noted 

 that these agreed exactly with the description given by M. Brong- 

 niart of the head of his species ; and one of Green's published casts 

 is from a British specimen. 



Professor Buckland, who in 1836 published a drawing of this 

 species in the Bridgwater Treatise, conceived it to be represented by 

 the more pointed form of P. macrophthalma, (Brongniart, fig. 4), and 

 named it accordingly ; and Sir E. I. Murchison followed this view, at 

 the same time rightly distinguishing it from the obtuse headed 

 species (fig. 5 of Brongniart), which occurs, though rarely, in com- 

 pany with it at Dudley. He considered the latter fossil, which has 

 enormous eyes, to be more properly the type of BrongTiiart's species ; 

 and gave the new name to that one which was conceived to repre- 

 sent his figure 4. Milne Edwards in 1840 recorded it as distinct 

 from either of Brongniart's species ; and as the French fossil with a 

 pointed front evidently furnished Brongniart with his description, 

 retained his name, Galym. macrophthalma, for that species, and gave 

 that of G. Bowningice to the present one. He also applied a new 

 name, (7. Stokesii, to the rarer British fossil represented by Brong- 

 niart's fig. 5. In this view all naturalists are now agreed. In the 

 meantime, and immediately after the publication of the Silurian 

 System, Professor Emmrich had established the very natural genus 

 Phacops for all those trilobites with largely facetted eyes and 11 

 segments to the thorax ; and he of course quoted the present species 

 under the genus, but supposed it might probably be a variety of his 

 Bohemian species, P. procevus. He afterwards, 1845, admitted it 

 under the present name. Professor Goldfuss, too, in the general sys- 

 tematic Eeview of Trilobites, published in the Neues Jahrbu:ch for 

 1843, had admitted the species; and perceiving the great distinction 

 that existed between those forms with all the glabella furrows 

 distinct and strong, and those in which the anterior ones were 

 obsolete, he separated the group which includes the present species 

 under the term A caste, reserving Phacops for those species with 

 inflated heads and obscure glabella fiirrows, which Dr. Emmrich 

 had already pointed out in his Dissertation as the type of his 

 genus. The latter, in his systematic table of the genera, pubHshed 

 in the Neues Jahrbuch for 1845, objected to this arrangement, and 

 grouped together the two sections just adverted to as constituting 



