NIAGARA FALLS AND VICINITY 



225 



margin obliquely inward to the eyes, and thence almost directly for- 

 ward, cutting the margin separately. Thorax with nine or 10 seg- 

 ments and grooved and falcate pleurae. Pygidium Jarge and flat, 

 the segments commonly ending in spinous prolongations. Doub- 

 lure very broad. 



Lichas boltoni (Bigsby) (Plate 17) (Hall. 1852. Pal. N. Y. 

 2:311, pi. 69, 70) 



Distinguishing characters. Large size; nasute anterior end; 

 large central and obHque lateral lobes of glabella; scabrous surface 

 with backward directed acute pustules; strongly striated doublure; 

 three broad lateral lobes of pygidium, contracting to angular ter- 

 minations. 



Found in the lower Rochester shale at Niagara. 'Rare and in 

 fragments. Common at Lockport and elsewhere (Hall). 



Genus encrinurus Emmrich 



[Ety. : encrinus; ou/>a ==tail (from the resemblance of the py- 

 gidium to a crinoid stem)] 



(1845. Neues Jahrb. p. 42) 



Cephaion narrow, wider than long, tuberculated; glabella pyri- 

 form, prominent; free cheeks narrow, separated in front; eyes small, 

 elevated, on conic prominences. Thoracic segments 11. Pygidium 

 triangular, with numerous segments. 



Encrinurus ornatus Hall & Whitfield <'. ' --^ /^. 

 (Fig. 157). Cybele punctata / ^1 



Hall (1852. Pal. N.Y. 2:297, pi A66) j 



Distinguishing characters. Strongly ] 



pustulose surface of cephaion ; pyrif orm % 

 glabella; elongate triangular pygidium, 

 with concavity along the center of the 

 axis, tuberculated at intervals; slender curving ridges of pygidial 

 limb, tuberculated at intervals. 



Found in the lower Chnton Hmestone at Niagara. Rare. Also 

 ^t Lockport (Hall). 





y 



W 



Fig. 157 Encrinurus ornatus 



