482 SILURIAN TRILOBITES OF NEW SOUTH AVALES, vi., 



thickening distally : axial furrows deep and distinct; fixed cheeks 

 large, tumid, steeply sloping into the axial furrows, highest at 

 the eye-lobes, always less elevated than the glabella; free cheeks 

 large, high, borders strongly thickened, corresponding with the 

 limb; marginal furrows shallow and wide, continuous with the 

 frontal and posterior furrows; eyes placed well outward from 

 the axial grooves; facial sutures straight anteriorly, posteriorly 

 for the first half straight outwardly and thence obliquely to 

 the lateral margin in front of the very rounded and rather 

 depressed genal angles. 



Thorax subrectangular, rather strongly inHated, surface ap- 

 parently granulate, length much less than the width in mature 

 specimens, and apparently about equal to twice the length of 

 cephalon; axis slightly less wide than the pleural lobes, strongly 

 arched, most strongly elevated towards the pygidium; bases of 

 each ring strongly tuberculate; pleural lobes of the usual Caly- 

 mene-type, axial groove distinct. 



Pygidium sub-semicircular or widely triangular when normal, 

 highly inflated, with a general tendency to droop, strongly gran- 

 ulated, with centrally a distinct arch in the posterior margin; 

 axis very strongly arched and prominent anteriorly, and dimin- 

 ishing rapidly in these features terminally; annulations five in 

 number, with a semicircular terminal piece (which is sepaiated 

 from the steeply bent-down, smooth, boss-like end by a low, 

 semicircular fillet) in all specimens, which have come under our 

 notice, up to three inches in length; some pygidia of the species 

 which exceed this length show seven or more annulations; pleurae 

 similar in character to those of thorax, and divided into five 

 segments, each succeeding one, from the front, becoming very 

 slightly more backwardly directed, until the last is reached, and 

 this one abruptly becomes parallel with the axial groove, making 

 the medial furrows of the fifth pair of pleurye unusually wide, as 

 they are in C. hlutnenbachii* 



Obs. — For some years past, we have looked upon the Bowning 

 ValymeiLe as the widely distributed C. biumeiibachii, but, after a 

 critical examination of many specimens, and careful study and 



"'■ Tills de^sciiption lias been made truni iion-testiferou.s specimens. 



