38 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxix. 



Olenoides duhia and Dorypygella alastor it differs in the slender axis 

 and spinose border of the pygidium. 



This is one of the finest of the trilobites collected by Mr. Black- 

 welder; and owing to the fact that there is a number of specimens of 

 the head and pygidium, and one specimen preserving the head attached 

 to twelve segments of the thorax, it is possible to separate it from the 

 genera Dorypyge and Olenoides and to establish a generic type, the 

 specimens of which have hitherto been confused with Dorypyge. It 

 is not impossible that an entire specimen of Olenoides leblanci would 

 prove that species to belong to the genus Damesella. 



Formation and locality. — Middle Cambrian; central portion of 

 Chang Hsia formation, in gray limestone, 3.25 miles and 6 miles south- 

 west of Yen Chuang, Hsin Tai. In talus, in dark limestone; 2.8 miles 

 and 6 miles southwest, and 2 miles south of Yen Chuang, Hsin Tai, 

 Shangtung, China, 



The stratigraphic range given this species is based upon the com- 

 parison of specimens that appear to be identical. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



DAMESELLA BELLAGRANULATA, new species. 



This species is represented b}'^ the central portions of the head, 

 exclusive of the free cheeks. These parts indicate that the head was 

 transversely semicircular and moderately convex. 



Glabella truncato-conical, moderately convex, and marked by two 

 pairs of ver}^ faintly indicated short furrows; occipital furrow nar- 

 row, transverse, clearly defined; occipital ring of moderate width and 

 slightly convex; dorsal furrow clearly defined on the sides of the 

 glabella; frontal border narrow, rounded. 



Fixed cheeks of nearly the same width as the glabella opposite the 

 palpebral lobes; they slope up very slightly from the dorsal furrow 

 to the palpebral lobe, and gently backward to the slight furrow within 

 the posterior margin; to the front they curve down rather rapidly to 

 the frontal border; ocular ridge narrow and faintly defined; palpebral 

 lobe a little more than one-fourth the length of the head, rising some- 

 what abruptly from the plane of the fixed cheeks; postero-lateral 

 limb from the dorsal furrow to its extremit}^ about the same length as 

 the width of the glabella at its base; it is marked by a shallow, nar- 

 row furrow some distance within the posterior margin. 



The surface is ornamented by rather large, closely arranged 

 pustules that cover the glabella and fixed cheeks; the pustules are 

 larger on the occipital segment and its extension on the postero-lateral 

 limbs and on the frontal border; larger pustules are also scattered on 

 the back portion of the head near the dorsal furrow. Over the spaces 

 between the larger pustules and on the pustules there is a minute 



