DESCRIPTION OF PLATE 13. 
Ptychoparia (Emmrichella) mantoensis (Walcott) (p. 136). 
1. Type specimen showing central part of cephalon, exclusive of postero-lateral limbs; and side outline 
of same, X 1.5. U.S. Nat. Mus., Cat. No. 57964. 
1a (X 2) and 1b (X 2). Associated free cheeks. U. 5. Nat. Mus., Cat. Nos. 57965 and 57966. 
1c. Associated pygidium, X 3. U.S. Nat. Mus., Cat. No. 57967. 
All of the specimens represented by figs. 1, 1a-c are from Locality C20, Lower Cambrian, south of 
Ch’ang-hia, Shan-tung. 
Ptychoparia (Emmrichella) theano (Walcott) (p. 136). 
2. Top and side views of type specimen, X 3. From Locality C23, Middle Cambrian, southeast of 
Ch’ang-hia, Shan-tung. U.S. Nat. Mus., Cat. No. 57603. 
Ptychoparia (Emmrichella) bromus (Walcott) (p. 135). 
3. Type specimen, showing central parts of cephalon, X 2. From Locality C6, Middle Cambrian, 
southwest of Yen-chuang, Shan-tung. U.S. Nat. Mus., Cat. No. 57969. 
Ptychoparia (Emmrichella) eriopia (Walcott) (p. 136). 
4. Top and side views of type specimen, showing central parts of cephalon, X 2. U.S. Nat. Mus., 
Cat. No. 57970. 
4a. Pygidium associated with specimen represented by fig. 4, X 2. U.S. Nat. Mus., Cat. No. 57971. 
From Locality © 23, Middle Cambrian, 1 mile (1.6 km.) east-southeast of Ch’ang-hia, Shan-tung. 
Ptychoparia (Emmrichella) constricta (Walcott) (p. 135). 
5. Type specimen, showing central parts of cephalon, except postero-lateral limbs. U.S. Nat. Mus., 
Cat. No. 57972. 
sa. Associated pygidium. U.S. Nat. Mus., Cat. No. 57973. 
The specimens represented by figs. 5 and 5a are from Locality C3, Lower Cambrian, Man-t’o shale 
formation, Hu-lu-shan, southwest of Yen-chuang, Sin-t’ai district, Shan-tung. 
Liostracus aculeatus Angelin. 
6, 6a, and 6b. Dorsal side and front views of a specimen from Borgholm, Sweden, X 3. U.S. Nat. Mus., 
Cat. No. 58293. 
Conocephalites emmrichi Barrande. 
7 and 7a. Dorsal and side views of dorsal shield. [After Barrande, Syst. Sil. de Bohéme, 1852, vol. 1, 
plate m1, figs. 4, 5.] 
Conocephalites ornatus Brogger. 
8. Central portion of cephalon. [After Brégger, Nyt Mag. Naturvid. vol. 24, 1877, plate 3, fig. 5.] 
Conokephalina vesta (Walcott) (p. 139). 
9. Dorsal and side views of the cranidium, X 4. U. S. Nat. Mus., Cat. No. 57974. 
oa. Associated free cheek, X 2. U. S. Nat. Mus., Cat. No. 57975. 
9b (X 3) and 9c (X 2). Associated pygidia. U.S. Nat. Mus., Cat. Nos. 57976 and 57977. 
The specimens illustrated by figs. 9, 9a-c are from Locality C 69, Middle Cambrian, east of Fang- 
lan-ch6n, Shan-si. 
Conokephalina sp. undt. (Walcott) (p. 140). 
to. Dorsal and side views of a small cranidium, X 5. From Locality C70, Middle Cambrian, south- 
southwest of Tung-yii, Shan-si. U.S. Nat. Mus., Cat. No. 57978. 
Conokephalina dryope (Walcott) (p. 138). 
11. Dorsal and side views of a broken cranidium, X 2. U.S. Nat. Mus., Cat. No. 57979. 
11a. Associated free cheek, X 3. U.S. Nat. Mus., Cat. No. 57980. 
11h. Dorsal and side views of an associated pygidium, X 2. U.S. Nat. Mus., Cat. No. 57981. 
‘The three specimens illustrated are from Locality C56, Upper Cambrian, 1 mile (1.6 km.) west of 
Tsi-nan, Shan-tung. 
Conokephalina belus (Walcott) (p. 138). 
12. Dorsal and side views of a cranidium, X 3. U.S. Nat. Mus., Cat. No. 57982. 
12a. Dorsal and side views of an associated pygidium, X 3. U.S. Nat. Mus., Cat. No. 57983. 
Both specimens illustrated are from Locality C56, Upper Cambrian, 1 mile (1.6 km.) west of Tsi-nan, 
Shan-tung. 
Conokephalina maia (Walcott) (p. 139). 
13. Dorsal view of a small broken cranidium, X 5. From Locality C70, Middle Cambrian, south- 
southwest of Tung-yii, Shan-si. U.S. Nat. Mus., Cat. No. 57984. 
Crepicephalus damia Walcott (p. 141). 
14. Type specimen, showing central parts of cephalon, and side outline of same, X 2. U.S. Nat. 
Mus., Cat. No. 57986. 
t4a. Associated free cheek, X 2. U. S. Nat. Mus., Cat. No. 57987. 
14b. Associated pygidium, X 2. U.S. Nat. Mus., Cat. No. 57988. 
The three specimens illustrated are from Locality C 18, Middle Cambrian, east of Ch’ang-hia, Shan-tung. 
Crepicephalus magnus Walcott (p. 142). 
15. Fragment of base of glabella, X 2. From Locality C48, Middle Cambrian, Ch’au-mi-tién, Shan- 
tung. U.S. Nat. Mus., Cat. No. 57992. 
15a. Fragment of a free cheek referred to this species on account of the coarse granulations. It is from 
Locality 025, Middle Cambrian, Ch’ang-hia limestone, at Ch’ang-hia, Shan-tung. U.S. Nat. 
Mus., Cat. No. 57993. 
15). Cast of interior of a free cheek and spine, associated with the specimen represented by fig. 15. 
U.S. Nat. Mus., Cat. No. 57994. 
Figures 15 and 15) represent specimens from the lower portion of the Ch’au-mi-tién limestone at C 48, 
Middle Cambrian, Ch’au-mi-tién, Shan-tung. 
Crepicephalus convexus Walcott (p. 140). 
16 and 16a. Two specimens of cranidium and side outline of 16, X 3. U.S. Nat. Mus., Cat. Nos. 
57996 and 57571, respectively. 
16b. Dorsal view of pygidium and side outline, X 3. U.S. Nat. Mus., Cat. No. 57572. 
The three specimens illustrated are from Locality 35r, Middle Cambrian, Fu-chou series, Liau-tung, 
Manchuria. 
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