186 RESEARCH IN CHINA. 
the palpebral lobes of 17 mm.; the glabella is 8 mm. in width, with a length, including 
the occipital ring, of 14 mm. 
This species differs from Ptychaspis cacus [plate 17, figs. 10, 11] in the globose, 
overhanging frontal lobe of the glabella, and the form of the frontal rim, features 
that also separate it from P. cadmus [plate 16, fig. 19] and P. calchas [plate 16, fig. 
13]. From P. acamus [plate 16, fig. 18] it differs in the form of the frontal lobe of 
the glabella and the transverse lobe back of it. The globose glabella resembles 
that of P. granulosa Owen [1852, p. 575], except that it is more globose and over- 
hangs the frontal border. Pitychaspis granulosa has a different form from the other 
Chinese species. 
Formation and Locality—Upper Cambrian: (C38) Crystalline limestone near 
the base of the Ch’au-mi-tién limestone [Blackwelder, 19074, p. 36 (part of first list 
of fossils)], at Ch’au-mi-tién, and (C34), purplish-gray limestone about 100 feet 
(30 m.) above the base of the Ch’au-mi-tién formation [idem], in road at northeastern 
corner of small village near Ch’au-mi-tién; also (C54), lower part of Ch’au-mi-tién 
limestone [idem, p. 42 (part of last list of fossils)], near top of limestone knoll two- 
thirds of a mile (1.1 km.) west of Tsi-nan; (C56), lower part of Ch’au-mi-tién lime- 
stone, 25 feet (7.5 m.) below the top of Pagoda Hill [idem], 1 mile (1.6 km.) west of 
Tsi-nan; and (C64), 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 Eliot Blackwelder. 
Ptychaspis ? spp. undt. Walcott. 
Plate 17, Figures 1, 6-8; Plate 21, Figures 14, 15. 
Ptychaspis sp. undt. WALcoTtT, 1905, Proc. U.S. Nat. Mus., vol. xx1x, p. 74. (Species referred to as in 
first paragraph below.) 
There are several species of Ptychaspis that occur in the Upper Cambrian zone 
that are too imperfect for description. One of these has the general form of P. 
campe, but it differs in the exceedingly narrow fixed cheeks and flat frontal border, 
while having the same type of pustulose surface. It occurs at Locality C47, Upper 
Cambrian, upper part of the Ch’au-mi-tién limestone [Blackelder, 1907a, fig. 9 
(top of bed 1), p. 35], at the top of a high col at Ch’au-mi-tién, Shan-tung, China. 
Free cheeks referred more or less doubtfully to the genus occur as follows: 
Plate 17, figure 1; plate 21, figure 14, at Locality C64, Upper Cambrian, upper 
limestone member of the Kiu-lung group [Blackwelder, 1907a, 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, Shan-tung. 
Plate 17, figure 6; plate 21, figure 15, at Locality C54, Upper Cambrian, lower 
part of Ch’au-mi-tién limestone [Blackwelder, 19074, p. 42 (partof last list of fossils)], 
near top of limestone knoll two-thirds of a mile (1.1 km.) west of Tsi-nan, Shan-tung. 
Plate 17, figure 7, at Locality C67, Upper Cambrian, stream gravels (these are 
taken from the wash from the mountains south of the city), used in making the 
railroad grade, one-third mile (0.5 km.) west of the west city gate at Tsi-nan, 
Shan-tung. 
Plate 17, figure 8, at Locality C33, Upper Cambrian, about 100 feet (30 m.) 
above the base of the Ch’au-mi-tién limestone, 9 miles (14.4 km.) north of Sin-t’ai- 
hién, Shan-tung, China. 
Also from Locality C50, Upper Cambrian, upper part of the Ch’au-mi-tién 
limestone [Blackwelder, 19074, p. 36 (part of third list of fossils)], on a low spur at 
Ch’au-mi-tién, Shan-tung, China. 
Collected by Eliot Blackwelder. 
