NO. 12 SPENCE SHALE AND ITS FAUNA RESSER I5 



OLENOIDES EVANSI, n. sp. 



Plate 4, figs. 3, 4 



This species is characterized by a quadrate glabella similar to species 

 of Kootcnia, but the pygidium has the true Olenoides feature of sepa- 

 rate pleura. It has seven pairs of spines. The pygidium of O. evansi 

 resembles that of 0. clongatus due to its triangular shape and elonga- 

 tion to accommodate seven spines. The occipital ring and thoracic seg- 

 ments each bear a small median spine or tubercle, which are lacking 

 from the axial rings of the pygidium. 



A crushed and poorly preserved hypostoma occurs with portions 

 of a few pygidia and is thought to belong to the species. 



Locality 556. 



Holotype and pai'afypc.—U .S.N .M. no. 96514. 



KOOTENIA Walcott, 1888 

 KOOTENIA IDAHOENSIS, n. sp. 



Plate 3, figs. 1-3 



This species belongs to the serrata group of the genus and is a 

 six-spined form. The cranidium has the usual quadrate outline and 

 proportions, and the surface is ornamented with lines and granules. 

 The neck spine is slender and not ver}^ long. 



The thorax has seven segments terminating in rather blunt spines, 

 which have the usual elongate, scaly granulations. 



Six blunt spines margin the pygidium. All spines are coarsely 

 granulated. 



LocaHty 55c. 



Holotype and parafypcs. — -U.S.N.M. no. 96505. 



KOOTENIA SPENCEI, n. sp. 



Plate 3, figs. 4, 5 



Only two incomplete pygidia have been found of this seven-spined 

 species. Unfortunately, neither pygidium is well preserved. The 

 pleural grooves remain on exfoliated specimens. Six pairs of the 

 marginal spines are long and slender, possibly attaining a length 

 greater than the pygidium. Each spine had a medial furrow for a 

 considerable distance from the border. The seventh pair of spines is 

 short. 



Locality 55c. 



Holotype and pavatypes. — U.S.N.M. no. 96506. 



