DESCRIPTION OF GENERA AND SPECIES. 157 



furrow; there are no traces of glabellar furrows; occipital ring strong, and merged 

 into the broad, subtriangular base of a strong, short spine; dorsal furrow shallow but 

 sufficiently strong to mark the line of demarcation between the glabella, fixed cheeks, 

 and frontal limb. 



Fixed cheeks a little more than half the width of the glabella, rising rapidly 

 from the facial suture and merging into the frontal limb anteriorly and into the short 

 postero-lateral limbs at the back; palpebral lobes small and narrow; palpebral 

 ridges broad but faintly defined; they extend from the antero-lateral angle of the 

 glabella outward and slightly backward to where they unite with the palpebral lobe ; 

 frontal limb slightly convex from the front of the glabella to the broadly rounded 

 front margin. 



Surface apparently smooth. 



The largest specimen in the collection has a length of 9 mm., exclusive of the 

 occipital spine. 



This species strongly suggests Agraulos strenuus Billings [18726, p. 473, fig. 10] 

 from the Paradoxides zone of Newfoundland; it differs in the form of the frontal 

 limb and border. In A. dolon the frontal limb arches gently downward and forward 

 to the margin, while in A. strenuus it is nearly flat and slightly convex between the 

 glabella and the margin. The glabella of the latter is also proportionately longer. 



It differs from Agraulos dirce [p. 156] in its greater convexity, more clearly 

 defined glabella, and strong occipital spine. 



Formation and Locality. Middle Cambrian : (C 7) Lower limestone member of 

 the Kiu-lung group [Blackwelder, 19070, pp. 37 and 39 (last list of fossils), and fig. 

 8a (bed 33), p. 29], 2.2 miles (3.5 km.) southwest of Yen-chuang, Sin-t'ai district, 

 Shan-tung, China. 



Collected by Eliot Blackwelder. 



Agraulos dryas Walcott. 



Plate 14, Figure 20. 



Agraulos dryas WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 36. (Described as a new species 

 essentially as below.) 



Glabella and fixed cheeks convex; rhomboidal in outline. Glabella convex, 

 short, narrowing slightly toward the rounded front, without traces of furrows ; occip- 

 ital furrow broad, very faintly defined ; occipital ring very narrow at the sides, broad- 

 ening out rapidly to a blunt point so as to be almost triangular. 



Fixed cheeks about two-thirds the width of the glabella, and sloping slightly 

 downward to the small palpebral lobes, which are situated about midway between 

 the posterior and the front margin of the cephalon; back of the palpebral lobes the 

 fixed cheeks slope rapidly to broad, short, postero-lateral limbs ; palpebral lobes short, 

 form unknown ; palpebral ridges not distinguished on the downward slope of the 

 fixed cheeks toward the frontal limb ; frontal limb and frontal rim nearly as long 

 as the glabella; very slightly convex and separated from each other by a shallow, 

 slightly defined depression; dorsal furrow shallow but clearly defined. 



Entire surface marked by numerous rather strong punctae ; also very fine, almost 

 microscopic, irregular, elevated, more or less concentric striae on the glabella. 



Length of cephalon, 3.5 mm. 



This species is represented by one specimen. It is strongly characterized by its 

 punctate surface and general form. 



Formation and Locality. Middle Cambrian: (029) Near the top of the cliffy 

 limestone in the Ch'ang-hia limestone [Blackwelder, 19070, p. 32 (part of last list of 

 fossils)], i mile (1.6 km.) west of Ch'ang-hia, Shan-tung, China. 



Collected by Eliot Blackwelder. 



