52 
BULLETIN OF THE LABORATORIES 
British Carboniferous 'brilobites 18S3-81 Palaeontographical Society, 
London. ) 
The first description of trilobite remains from carboniferous rocks 
was that of the Abbe' de Vitry in 1779. (3 Mem. de I’Acad. imper. 
et royale des sciences et belles lettres de Bruxelles, 1780.) Thirty 
years later William Martin described in his Petrihcata Derbiensia a 
toilobite as Entomolithus onicites Derbyensis, which he regarded as a 
petrified insect related to Oniscus. 
In 1836, Phillips’ Geology of Yorkshire appeared, in which eight 
species were described, albeit very imperfectly. 
Portlock, in 1843, published his Geological Report on London- 
derry in which for the first time the attempt was made to set up distinct 
genera for the carboniferous trilobites. Phillipsia .2iX\d GfiffithideSy 
the two prominent genera, date from this report. 
De Koninck added much to the general fund of information, 
although his studies were restricted to Belgium. 
M’Coy’s Synopsis of the characters of the carboniferous Lime- 
stone Fossils added several species although none too well distinguished. 
Family Proei'id/e. 
The four genera, Phillipsia, Griffithides, Brachymetopus, and 
Proetus, which constitute the family are all found in carboniferous 
rocks, while the first three are restricted to it, and Proetus begins in 
the Silurian. Phillipsia ‘and Griffiides really constitute one genus with 
two types more or less closely united. In both, the general form is 
oval, the angles of the cheeks may be greatly produced, facial suture 
cutting obliquity across the posterior margin of the head-shield ; 
thoracic segments nine in number ; pigidium with 12-18 segments, 
margin rounded, not fimbriated. 
Genus i. Phillipsia, Portlock, 1843. 
Glabella with nearly parallel sides ; basal lobes, formed by a well 
defined furrow separating the posterior corners, distinct ; middle of 
glabella marked by two or more lateral furrows ; eyes large, facetted ; 
cervical furrow deep. 
Genus 2. Griffithides, Portlock, 1843. 
Glabella, pyriforme, tumid, destitute of lateral furrows, eyes 
small smooth, cervical lobe broad. 
