OLENELLUS AND OTHER GENERA OF MESONACID.E 407 



Oleiielliis gilberti Meek (continued) : 



14 and 14a. Top and side view of a small cephalon with fine antero- 

 lateral and intergenal spines. X 8. U. S. National Museum, 

 Catalogue No. 56828J. 



15. Small cephalon X 4, in which the antero-lateral angles have dis- 



appeared and the palpebral lobes become relatively shorter. 

 U. S. National Museum, Catalogue No. s6828£'. 



16. K large cephalon doubtfully referred to this species. Natural 



size. U. S. National Museum, Catalogue No. 56829«. 



17. Fragment of a cephalon that appears to belong to this species. 



Natural size. U. S. National Museum, Catalogue No. 568296. 

 The specimens represented by figs. 11-15 are from locality 

 (35O. Ptarmigan Pass, Alberta; those by figs. 15-17 from 

 locality (350> above railway tunnel, Mt. Stephen, British Co- 

 lumbia, on the main line of the Canadian Pacific Railway. 



