184 RESEARCH IN CHINA. 



Fixed cheeks narrow, rising abruptly from the dorsal furrow and extending 

 laterally to the furrow within the rim of the palpebral lobe ; they slope gently back- 

 ward to the postero-lateral limb, and more abruptly forward to a strong furrow 

 that separates the frontal, rounded margin of the cephalon from the glabella; 

 frontal limb and rim combined in a rounded frontal border, which corresponds in 

 its section to about the same curvature as the section of the furrow between the 

 border and the glabella; postero-lateral limbs about as long as the width of the 

 glabella, and marked by a broad, rather deep groove within the narrow posterior 

 margin. 



Surface of the cast of the interior of the test with numerous rather large, 

 scattered punctas, and very fine punctse seen only with the aid of a strong lens; a 

 fragment of the outer surface shows it to have been strongly punctate, with fine 

 punctae corresponding to the punctse seen on the interior. 



The largest cephalon in the collection has a length of 13 mm. 



This species is strongly characterized by the broad, strong posterior furrow and 

 narrow posterior lobe of the glabella, and the subquadrate, moderately convex 

 frontal lobe; also the elevated occipital ring and punctate surface. 



Formation and Locality. Upper Cambrian: (C64) Upper limestone member 

 of the Kiu-lung group [Blackwelder, 19070, pp. 37 and 42 (first list of fossils), and 

 fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) southwest of Yen-chuang, Sin-t'ai district, 

 Shan-tung, China. 



Collected by Eliot Blackwelder. 



Ptychaspis calyce Walcott. 

 Plate 16, Figures 15, 150. 



Ptychaspis calyce WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 72. (Characterized as a new 

 species as below.) 



In general form, convexity, and size the corresponding parts of this species 

 follow those oiP.celo [plate 1 6, fig. 17]. It differs from the latter in having a strongly 

 pustulose surface instead of irregular, more or less concentric ridges and furrows. 

 The largest specimen of the cephalon in the collection has a length of 17 mm. 



Formation and Locality. Upper Cambrian: (C42) In the central part of the 

 Ch'au-mi-tien limestone [Blackwelder, 19070, p. 36 (second list of fossils)], 1.8 miles 

 (2.9 km.) west-southwest from the temple on Tsing-lung-shan, 7.5 miles (12 km.) 

 east of Ch'au-mi-tien, Shan-tung; also (064), upper limestone member of the Kiu- 

 lung group [idem, pp. 37 and 42 (first list of fossils), and fig. 10 (bed 20), p. 38], 2.7 

 miles (4.3 km.) southwest of Yen-chuang, Sin-t'ai district, Shan-tung, China. 



Collected by Bailey Willis and Eliot Blackwelder. 



Ptychaspis campe Walcott. 

 Plate 1 6, Figure 16. 



Ptychaspis campe WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 73. (Described as a new 

 species essentially as below.) 



This species is represented by a fragment of a small cephalon that is so distinct 

 in its surface granulation, large eye-lobe, and frontal portion of the cephalon that it 

 can not be readily confused with any other species. The glabella is divided by two 

 narrow, transverse, slightly backward curving furrows into two narrow lobes and a 

 large anterior lobe that is marked by two pairs of short, very narrow furrows on the 

 lateral slopes ; the anterior lobe is about as long as wide, slightly convex behind and 



