400 Prof. F. M‘Coy on the Classification of 
and duplicate lateral furrows; thoracic segments ten, pleural 
grooves slightly oblique, facets large. 
Subgen. 1. Forbesia (M‘Coy) = onia, Burm. Cephalic 
angles produced; glabella with three pair of segmental 
furrows ; ends of neck-segment forming large tubercles. 
Subgen. 2. Pretus (Stein.). Cephalic angles not produced ; 
no segmental furrows to glabella. 
7. Purists (Portk., extended). General character of Forbesia, 
but only nine thoracic segments. (Carboniferous.) 
Subgen. 1. Phillipsia (Portk.). Base of glabella wide, sides 
with three segmental furrows. 
Subgen. 2. Griffithides (Portk.). Base of glabella contracted, 
sides without segmental furrows. 
2nd Subfam. Parapoxina”. 
Head large ; pygidium diminutive ; thorax long ; pleure flat, not 
bent down at the end, terminating m 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 pleure are 
produced backwards into sharp spines. None of these can roll 
into a ball. 
1. Parapoxipgs (not British). 
Subgen. 1. Olenus (Dal.). Fourteen thoracic segments ; 
pygidium small, with entire margin. 
2. Ceraurus* (Green, emended by 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 ; pleurz each 
with a short oblique pleural groove dividing its tumid origin, 
ends flat, faleate ; pygidium moderate, the margin with six or 
eight thick spines ; cephalic angles prolonged. 
3. Crypuaus (Green) =? Eccoptochile (Hawle and Corda). Head 
as in Ceraurus; twelve thoracic segments ; pleure 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, Spu#rexocuvs (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 (Paleontology of New York), of Green’s 
original specimen of Ceraurus, showing all the characters of the Bohemian 
genus. 
