DESCRIPTION OF GENERA AND SPECIES. 125 



Damesella bellagranulata Walcott. 

 Plate 9, Figures 8, Sa-b. 



Damesella bellagranulala WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 38. (Described and 

 discussed as a new species essentially as below.) 



This species is represented by the central portions of the cephalon, exclusive of 

 the free cheeks. These parts indicate that the cephalon was transversely semicir- 

 cular and moderately convex. Glabella truncato-conical, moderately convex, and 

 marked by two pairs of very 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 ; palpebral ridge narrow and faintly 

 defined ; palpebral lobe a little more than one-fourth the length of the cephalon, ris- 

 ing somewhat abruptly from the plane of the fixed cheeks; postero-lateral limb, from 

 the dorsal furrow to its extremity, about the same length as the width of the glabella 

 at its base ; it is marked by a shallow, narrow furrow some distance within the pos- 

 terior 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 granulation 

 that gives a very highly ornamented surface under a strong lens. 



The type and only specimen of the cephalon in the collection has a length of 

 12 mm., of which the glabella occupies 9 mm. ; the width at the outside of the pal- 

 pebral lobes is 17 mm. and at the ocular ridges 5.5 mm. 



The cephalon of this species is much like that of Damesella blackwelderi in gen- 

 eral form, but it differs in the elevated eye-lobes and the peculiarly ornamented, 

 pustulose surface. 



Formation and Locality. Middle Cambrian: (CIS) Yellow slabby limestone 

 in the middle limestone member of the Kiu-lung group [Blackwelder, 19070, pp. 37 

 and 41 (part of first list of fossils)], on the west slope of hill in angle between two faults 

 just east of the granite mass of the Lien-hua-shan, 6 miles (9.6 km.) southwest of 

 Yen-chuang, Sin-t'ai district, Shan-tung, China. 



Collected by Bailey Willis. 



Damesella blackwelderi Walcott. 



Plate 10, Figures i, la-j. 



Damesella blackwelderi WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 35. (Described and dis- 

 cussed as a new species essentially as below.) 



General form ovate, moderately convex; distinctly trilobed, the central axis 

 rather convex and the pleural lobes more or less flattened. 



Cephalon transversely semicircular; frontal margin rounded and narrow in 

 young individuals, becoming broader and more flattened with increase in size; it 

 continues around the sides and the postero-lateral angle to unite with the narrow- 

 ing posterior margin. A postero-lateral spine projects backward and slightly out- 

 ward from a point on the margin a little in advance of the postero-lateral angle. 



