3ir, 



Fig. 258. Cryphceus 

 boothi, var. calliteles. Py- 

 gidium (after Hall and 

 Clarke). 



common, and it occurs in the shales below the Trilobite 

 beds in Avery's Creek. 



Cryph.^us boothi, var. calliteles. Green. (Fig-. 258.) 

 (Pal. N. Y., Vol. VII., p. 45, Pis. XVI., XVI.A.) 



Distinguishing Clmracters.—Long, flat, tapering genal 

 spines, their acnte extremity reaching to 

 the eighth thoracic segment, their 

 flattened end grooved by the occipital 

 furrow ; wide occipital ring, with cen- 

 tral spiniform node ; thorax annnlations 

 with spiniform nodes, increasing in size 

 backwards; distant, narrow, lanceolate 

 pygidial spines ; faintly granulose surface, with glabella and 

 pygidial lobes usually quite smooth. 



Found in the Encrinal limesttme, at Section 5 (rare) ; also 

 in the Trilobite beds of Section 8, etc., associated with the 

 preceding. 



Genus PROETIIS. Steininger. 



[Ety. : Mythological name.] 

 (1831: Mem. Soc. Geol. de France.) 



Cephalon semi-circular, with thickened margins. Glabella 

 very convex, parabolic, rounded anteriorh', with few lateral 

 furrows. Eyes prominent, smooth, 

 close to the glabella. Thoracic seg- 

 ments ten, pleurae with oblique fur- 

 row. Pygidium trilobed, semi-circu- 

 lar ; axis short and convex. 



Proetus macrocephalus. Hall. 

 (Fig. 259.) (Pal. N. Y., Vol. VII., p. 

 116, Pis. XXL, XXIII.) 



Distinguisliing Characters. — S u b - 

 semi-circular or lunate cephalon ; thin 

 acute genal spines ; sub-conate, pustu- 

 loseglabella,Avith sides broadly taper- 

 ing to the anterior extremity, its p-io 259 Pro^us ,>,acn,- 

 width three-fourths the length ; single ^i^c'^i-ter h^i and cM)."" 



