DESCRIPTION OF GENERA AND SPECIES. 199 



as long as the width of the glabella, narrow, and marked by a longitudinal groove; 

 in front of the glabella a narrow frontal limb slopes downward to a slightly convex, 

 flattened frontal rim about three times as long as the frontal limb. 



Surface minutely punctate. 



Length of the largest cephalon, exclusive of the occipital spine, 8 mm. 



This little species appears to be quite distinct from any other form of the genus. 

 Its narrow fixed cheeks, relatively large eye-lobe, and flattened frontal rim are the 

 characteristics upon which it is referred to Anomocaretta. 



Formation and Locality. Middle Cambrian: (C2) Lower shale member of the 

 Kiu-lung group [Blackwelder, 19070, pp. 37 and 40 (part of the third list of fossils), 

 and fig. 10 (beds 4 and 5), p. 38)], 2 miles (3.2 km.) south of Yen-chuang, Sin-t'ai 

 district, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Anomocarella butes ( Walcott) . 

 Plate 19, Figures 7, ja-d. 



Anonwcare (?) bides WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 49. (Described as a new 

 species essentially as below.) 



General form of cephalon semicircular, moderately convex. Glabella sub- 

 quadrilateral in outline, narrowing slightly toward the nearly transverse front; 

 marked by three pairs of slightly impressed, short furrows and a low, narrow median 

 ridge; occipital furrow shallow, rounded, and arching very slightly toward the 

 center; occipital ring slightly convex and of moderate width throughout, marked 

 by a minute, pointed node at the center; dorsal furrow rounded, distinct. 



Fixed cheeks less than one-half the width of the glabella ; they rise with a gentle 

 slope from the dorsal furrow to the furrow within the rim of the palpebral lobe; 

 slope back into the postero-lateral limb, and somewhat abruptly downward in front 

 of the palpebral ridge into the frontal limb; palpebral ridge clearly defined and 

 merging into the rim of the palpebral lobe ; the latter is a little more than one- third 

 the length of the cephalon; postero-lateral limb nearly as long as the width of the 

 glabella at the base, narrow, and marked by a strong groove within the rounded 

 posterior margin; frontal limb slightly convex and curving downward to the flat- 

 tened frontal rim ; the rim is a little longer than the length of the limb in front of 

 the glabella, and the line of demarcation between the limb and the rim is little more 

 than the angle formed by the union of the nearly flat rim with the inclined frontal 

 limb. 



Free cheeks irregularly triangular; marginal border flattened, strong, and pro- 

 duced behind into a strong, flattened spine ; central area slightly convex, and rising 

 rather abruptly to the base of the eye-lobe; anteriorly the border of the cheeks 

 narrows to a slender point. 



Thorax unknown. 



Associated pygidium semicircular in outline, convex; axis convex about two- 

 thirds the length of the pygidium, and divided by four furrows into four rings and a 

 terminal, longer ring, upon which a slight depression on each side indicates a fifth 

 furrow; the pleural lobes extend out about one-half of the distance nearly flat, 

 and then curve somewhat abruptly downward to a rather broad, flattened margin, 

 into which they merge ; the four grooves on the axis and the fifth groove just within 

 the interior margin extend across the pleural lobes, fading out on the flattened 

 margin. Two small nodes occur at the posterior end of the axis, through which a low, 

 broad, rounded ridge extends backward and downward into the flattened margin. 



