156 RESEARCH IN CHINA. 



Agraulos abrota Walcott. 

 Plate 15, Figure 3. 



Agraulos abrota WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 43. (Characterized as a new 

 species as below.) 



This species is represented by several small cephala, exclusive of the fixed 

 cheeks. It is closely related to Agraulos dryas [p. 157] but differs from it in its 

 greater width, stronger convexity of the glabella, and greater downward slope of the 

 frontal margin. The surface is also more minutely punctate than that of Agraulos 

 dryas. The largest specimen is a little less than 3 mm. in length. 



Formation and Locality. Middle Cambrian: (023) Upper part of thin-bedded 

 gray oolitic limestone at the base of the Ch'ang-hia formation [Blackwelder, 19070, 

 p. 32 (second list of fossils), and fig. 6 (bed 20), p. 25], 50 feet (15 m.) below the base 

 of the cliffs i mile (1.6 km.) east-southeast of Ch'ang-hia, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Agraulos dirce Walcott. 

 Plate 15, Figure 5. 



Agraulos dirce WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 44. (Described and discussed as 

 a new species essentially as below.) 



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

 the fixed cheeks. The surface is depressed, convex, with the glabella rising but 

 little above the general surface at the front, and but moderately convex at the base. 

 Glabella truncato-conical, indistinctly defined from the frontal rim and at its base 

 from the occipital ring; without traces of furrows; occipital furrow indicated only 

 by the very slight convexity of the occipital ring. 



Fixed cheeks about three-fourths of the width of the glabella ; posteriorly they 

 merge into the short postero-lateral limbs and toward the front into the broad, 

 gently convex frontal limb, which continues uninterruptedly to the anterior margin 

 of the cephalon; palpebral lobes small; palpebral ridges indicated by a dropping 

 down of the fixed cheek at the place where the ridges usually occur. 



This species recalls the general form of Agraulos strenuus Billings [18726, p. 473, 

 fig. 10]. It differs in being less convex, in its broader fixed cheek, and short occipital 

 ring. It also differs in its wider fixed cheeks from A. dolon, which occurs at about 

 the same geologic horizon. 



The largest cephalon in the collection has a length of n mm., and the same 

 width at the palpebral lobes. 



Formation and Locality. Middle Cambrian: (052) in the lower part of the 

 lower limestone member of the Kiu-lung group [Blackwelder, 19070, pp. 37 and 39 

 (second list of fossils), and fig. 7 (bed 22), p. 27], near base of cliffs in mountain i ,000 

 feet (305 m.) high, 3 miles (4.8 km.) north-northeast of Sin-t'ai-hien, Shan-tung, 

 China. 



Collected by Eliot Blackwelder. 



Agraulos dolon Walcott. 

 Plate 15, Figure 6. 



Agraulos dolon WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 45. (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. The glabella and fixed cheeks are convex, somewhat rhomboidal in 

 outline; glabella convex, narrowing slightly toward the broadly rounded frontal 

 margin ; posteriorly it is separated from the occipital ring by a very faint, narrow 



