NO. 24 PTARMIGANIA STRATA RESSER 47 



shallow marginal furrow. The five pairs of marginal spines are flat, 

 moderately long and slender, the anterior being the shortest, the 

 second somewhat larger, and the remaining three still larger and about 

 equal in size. 



The surface of the cranidium is marked by strong striae on the 

 frontal rim. On the sloping parts of the cranidium irregular lines 

 pass into more or less definite granules, except in the furrows. The 

 pygidium is covered with granulations, which tend to become scaly 

 on the marginal spines. 



Localities 54s, 59L 



Holotype and paratypes. — U.S.N.M. Nos. 98532a-e. 



KOOTENIA MALADENSIS, n. sp. 



Plate 10, figs. 12-15 



Associated with K. convoluta and K. granulosa are several entirely 

 smooth specimens of both cranidia and pygidia. Aside from lack of 

 granulation the cranidium is much like that of K. granulosa, except 

 that the rim in front of the glabella is narrower. Besides the smooth 

 test the pygidium is also somewhat flatter as a whole, and the ribs are 

 less conspicuous than in the other species. 



Locality 54s. 



Holotype and paratype. — U.S.N.M. Nos. 98533a, b. 



KOOTENIA GRANULOSA, n. sp. 



Plate 10, figs. 16-20 



This is a small, very beautiful species associated with K. convoluta 

 from which it differs in that the glabella is more quadrate in front 

 owing to shallower dorsal pits. The frontal portion of the rim is 

 slightly wider. K. granulosa is particularly characterized by the 

 rounded granules, which do not tend to form ridges. 



The pygidium referred to K. granulosa differs from that of K. 

 convoluta in having slightly deeper pleural furrows, less fusion of 

 the segments, less rapidly tapering marginal spines. It also has the 

 characteristic granulose surface. 



Locality 54s. 



Holotype and paratypes. — U.S.N.M. Nos. 98534a-e. 



KOOTENIA NITIDA, n. sp. 

 Plate 10, fig. 21 

 This species is founded on a single cranidium and is closely allied 

 to K. granulosa. K. nitida differs chiefly in its narrower glabella with 

 4 



