L 



TRILOBITA—OPISTHOPARIA. 



271 



2,7. N. serratus Rominger. (Fig. 1566.) Cambric. 



Glabellar furrows three, giving four lobes to each side of the 

 glabella; axis of neck furrow very broad. Surface granular. 



Middle Cambric of British Columbia. 



38. N. superbus Walcott. (Fig. 1567, a, &.) Cambric. 

 Pleural spines produced backwards but slightly. Surface marked 



with irregular raised lines. 

 Middle Cambric of Utah. 



39. N. inflatus Walcott. (Fig. 1567, c-^.) Cambric. 

 Glabella very broad anteriorly. Pygidium with many united 



segments. Surface as in N. superbus. 

 Middle Cambric of Utah. 



Fig. 1567. a, b, Neolenus superbus^ entire individual and large cranidium, X Yz > 

 c-e^ N. inflatus : Cy side and d, top view of cranidium ; e, pygidium, X /^ > /> ■^* 

 intermedms, pygidium, %. ( After Walcott. ) 



40. N. intermedius Walcott. (Fig. 1567,/.) Cambric. 



Intermediate between N. superbus and N. inflatus. No occip- 



