DESCRIPTION uF 1'l.ATii 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. 



ia (X 2) and ib (X 2). Associated free cheeks. U. S. Nat. Mus., Cat. Nos. 57965 and 57966. 

 ir. Associated pygidium, X 3- U. S. Nat. Mus., Cat. No. 57967. 

 All of the specimens represented by figs, i, la-c are from Locality 020, 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 06, 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. 



4d. Pygidium associated with specimen represented by fig. 4, X 2. U. S. Nat. Mus., Cat. No. 57971. 

 From Locality 023, Middle Cambrian, i 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. 



5<z. Associated pygidium. U. S. Nat. Mus., Cat. No. 57973. 

 The specimens represented by figs. 5 and 50 are from Locality 03, Lower Cambrian, Man-t'o shale 



formation, Hu-lu-shan, southwest of Yen-chuang, Sin-t'ai district, Shan-tung. 

 Liostracus aculeatus Angelin. 



6. 60, and 66. 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 ^a. Dorsal and side views of dorsal shield. (After Barrande, Syst. Sil. de Boheme, 1852, vol. I, 



plate II, figs. 4, 5.] 

 Conocephalites ornatus Brogger. 



8. Central portion of cephalon. [After Brogger, 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. 

 90. Associated free cheek, X 2. U. S. Nat. Mus., Cat. No. 57975. 



9& (X 3) and gc (X 2). Associated pygidia. U. S. Nat. Mus., Cat. Nos. 57976 and 57977. 



The specimens illustrated by figs. 9, ga-c are from Locality C 69, Middle Cambrian, east of Fang- 



lan-chon, Shan-si. 

 Conokephalina sp. undt. (Walcott) (p. 140). 



10. Dorsal and side views of a small cranidium, X 5. From Locality C70, Middle Cambrian, south- 



southwest of Tung-yu, 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. 

 i ia. Associated free cheek, X 3. U. S. Nat. Mus., Cat. No. 57980. 



lib. Dorsal and side views of an associated pygidium, X 2. U. S. Nat. Mus., Cat. No. 57981. 



The three specimens illustrated are from Locality 056, Upper Cambrian, i 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. 



120. Dorsal and side views of an associated pygidium, X 3. U. S. Nat. Mus., Cat. No. 57983. 

 Both specimens illustrated are from Locality 056, Upper Cambrian, i 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 070, Middle Cambrian, south- 



southwest of Tung-yu, 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. 



140. Associated free cheek, X 2. U. S. Nat. Mus., Cat. No. 57987- 

 146. 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 048, Middle Cambrian, Ch'au-mi-tien, Shan- 



tung. U. S. Nat. Mus., Cat. No. 57992. 



150. 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. 

 156. 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 156 represent specimens from the lower portion of the Ch'au-mi-tien limestone at 048, 



Middle Cambrian, Ch'au-mi-tien, Shan-tung. 

 Crepicephalus convexus Walcott (p. 140). 



16 and 160. Two specimens of cranidium and side outline of 16, X 3. U. S. Nat. Mus., Cat. Nos. 



57996 and 57571, respectively. 



i6b. Dorsal view of pygidium and side outline, X ,v I'. S. Nat. Mus., Cat. No. 57572. 

 The three specimens illustrated are from Locality 35 r, Middle Cambrian, Fu-chou series, Liau-tung, 

 Manchuria. 



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