400 Prof. F. JVl^Coy on the Classification of 



and duplicate lateral furrows ; thoracic segments ten, pleural 

 grooves slightly oblique, facets large. 



Subgen. 1. Forhesia (M^Coy) = JEonia, Burm. Cephalic 

 angles produced; glabella with three pair of segmental 

 furrows ; ends of neck-segment forming large tubercles. 



Subgen. 2. Proetus (Stein.). Cephalic angles not produced ; 

 no segmental furrows to glabella. 



7. Phillipsia (Portk., extended). General character of Forbesia, 

 but only nine thoracic segments. (Carboniferous.) 



Subgen. 1. P hillipsia (Portk.). Base of glabella wide, sides 



with three segmental furrows. 

 Subgen. 2. Griffithides (Portk.). Base of glabella contracted, 



sides without segmental furrows. 



2nd Subfam. ParadgxintE. 



Head large ; pygidium diminutive ; thorax long ; pleurse flat, not 

 bent down at the end, terminating in long spines ; pleural 

 grooves straight ; no facets. 



An easily recognized group of long-bodied, flat Trilobites with 

 large heads, the angles of which and the ends of the pleurse are 

 produced backwards into sharp spines. None of these can roll 

 into a ball. 



1. Paradoxides (not British). 



Subgen. 1. Olenus (Dal.). Fourteen thoracic segments ; 

 pygidium small, with entire margin. 



2. Ceraurus* (Green, emended hy Hall). Glabella cylindrical, 

 reaching the front margin, with three pair of segmental fur- 

 rows ; facial suture cutting the outer margin considerably in 

 front of the angles ; eleven thoracic segments ; pleurse each 

 with a short oblique pleural groove dividing its tumid origin, 

 ends flat, falcate ; pygidium moderate, the margin with six or 

 eight thick spines ; cephalic angles prolonged. 



3. CryphvEUS (Green) = t Eccoptochile (Hawle and Corda). Head 

 as in Ceraurus ; twelve thoracic segments ; pleurse wide, di- 

 vided by a long mesial pleural furrow not reaching the margin ; 

 ends thickened and each extended in a slender spine ; pygi- 

 dium of three thin flat lobes on each side. 



4. Sph^rexochus (Beyrich). Glabella hemispherical ; posterior 

 pair of segmental furrows very large, circular, two anterior 

 pair rudimentary or absent ; lateral angles rounded, divided 



♦ Chirurus (Beyrich) is I think certainly a synonym of this genus; the 

 recently published figures by Hall ( Pal ae ontology of New York), of Green's 

 original specimen of Ceraurus, showing all the characters of the Bohemian 

 genus. 



■ , .. .' 1 Jv 



