NO. 24 PTARMIGANIA STRATA- — RESSER 41 



elevation attained by an even curvature. The glabellar and occipital 

 furrows are shallow, and the occipital spine is heavy and long. The 

 palpebral lobes are just half the glabellar width at their widest point. 

 The associated pygidium is well fused, although both the furrows 

 and grooves are visible. The anterior portion of each pleuron is 

 elevated into a narrow ridge, particularly well shown in the side view 

 of the pygidium. The border is rather even, forming a slight angle 

 near the anterior corner and another toward the rear, the remnants 

 of the marginal spines. A small hypostoma lying near the cranidium 

 is thought to represent the species. Surface appears to have been 

 fairly smooth. 



Locality 54s. 



Holotype and paratype. — U.S.N.M. Nos. 98520a, b. 



PTARMIGANIA GERMANA, n. sp. 



Plate 7, figs. 16-20 



This is a relatively small species and is represented by several 

 cranidia and pygidia. The glabella expands considerably forward and 

 the usual furrows are visible but shallow. The occipital spine evidently 

 is rather slender. This species is quite flat in cross section and only 

 gently curved longitudinally. The eyes are long, gently curved, with 

 the eye band well defined. The pygidium is well fused, so much so 

 that most of the furrows and grooves are eliminated. The anterior 

 furrow is visible and the groove between the first and second pleura 

 is well shown next to the dorsal furrow, because of the ridging on 

 both sides of it. The rear margin is sharply indented in the center and 

 a very short spine is present at the anterior angles. 



Locality 54s. 



Holotype and paratypes. — U.S.N.M. Nos. oi>52ia-c. 



PTARMIGANIA DIGNATA, n. sp. 



Plate 8, figs. 1-7 



This is a well-represented species. The glabella expands forward 

 throughout its length ; at an increasing rate in the anterior third. The 

 furrows are shallow throughout. The occipital spine is of about 

 medium size and stands erect. The palpebral lobes are about half the 

 width of the glabella at the same point and are particularly character- 

 ized by high relief. A -ridge parallels the palpebral furrow, thus giving 

 rise to the distinctive feature of the species. The palpebral furrow is 

 broad and shallow and the eye bands narrow. The eyes are of medium 

 size and set at a considerable angle to the dorsal furrow. The flanges 



