DESCRIPTION OF PLATE 8. 



Dorypyge richthofeni Dames (p. 108). 



i Cranidium with finely granulated surface (X 1.5). and side outline. From Locality C 1, Middle Cam- 

 brian, Kiu-lung group, south of Yen-chuang, Shan-tung. U. S. Nat. Mus., Cat. No. 57876. 



10 Central parts of a cephalon, showing glabellar furrows and coarse granulations, X 1.5. From 

 Locality C 19, Middle Cambrian, Ch'ang-hia limestone at Ch'ang-hia, Shan-tung. U. S. Nat. 

 Mus., Cat. No. 57878. 



ib. Cranidium, showing postero-lateral limb, base of occipital spine, and glabella like that of fig. i, with 

 which it is associated in the limestone. (C 1.) U. S. Nat. Mus., Cat. No. 57877. 



ic. Top and side views of pygidium associated with io, X 1.5- (C 19.) U. S. Nat. Mus., Cat. No. 57879. 



id Thoracic segment, showing straight pleural groove, X 2. From Locality C29, Middle Cambrian, 

 Ch'ang-hia limestone, west of Ch'ang-hia, Shan-tung. U. S. Nat. Mus., Cat. No. 57881. 



if Fragmentary pygidium with very cylindrical axis. Natural size. From Locality C57, Middle 

 Cambrian, Kiu-lung group, north of Sin-t'ai-hien, Shan-tung. U. S. Nat. Mus., Cat. No. 57882. 



i/. Hypostoma associated with ia, X 1.5. (C 19.) U. S. Nat. Mus., Cat. No. 57880. 



Dorypyge richthofeni laevis Walcott (p. 109). 



2 . Top view and side outline of central parts of cephalon, X i .5 . From Locality C 72, Middle Cambrian, 



Ki-chou formation, east of Fang-lan-chon, Shan-si. U. S. Nat. Mus., Cat. No. 57883. 



20.. Free cheek associated with the cranidium represented by fig. 2, X 2. U. S. Nat. Mus., Cat. No. 

 57884. 



2ft. Hypostoma, X 2. From Locality C'71 (same horizon as fig. 2), Middle Cambrian, Ki-chou forma- 

 tion, southwest of Tung-yii, Shan-si. U. S. Nat. Mus., Cat. No. 57885. 



Dorypyge bispinosa Walcott (p. 107). 



3. Enlarged view of the type specimen; and side outline, X 1.5. From Locality C 2, Middle Cambrian, 



Kiu-lung group, south of Yen-chuang, Shan-tung. U. S. Nat. Mus., Cat. No. 57886. 



Stephanocare ? sinensis (Bergeron) (p. 116). 



4. Partly exfoliated pygidium, X 3. From Locality Cfi, Middle Cambrian, Kiu-lung group, south- 



west of Yen-chuang, Shan-tung. U. S. Nat. Mus., Cat. No. 57872. 



This specimen is on a slab of limestone with specimens of Blackwelderia sinensis. [See plate 9, fig. 50.] 



40. View ( X 4) of under side of pygidium, showing doublure and the irregular spines of the border, from 

 same locality (C6) as specimen represented by fig. 4. U. S. Nat. Mus., Cat. No. 57873. 



Stephanocare ? monkei Walcott (p. 113). 



5. Pygidium doubtfully referred to this genus ( X 2). It is associated with Stephanocare ? sinensis and 



5. sp. undt., fig. 6. From Locality C 6, Middle Cambrian, Kiu-lung group, southwest of Yen- 

 chuang, Shan-tung. U. S. Nat. Mus., Cat. No. 57601. 



Stephanocare sp. undt. Walcott (p. 116). 



6. A minute pygidium, X 4, tentatively referred to this genus, associated with Stephanocare ? monkei, 



fig. 5. U. S. Nat. Mus., Cat. No. 57875. 



Olenoides nevadensis (Meek). 



7. Two segments of thorax of type specimen that show the broad, straight pleural groove. Note the 



broad node at the inner end of the groove next to the axis that narrows the groove and bends 

 it forward. From Locality 3s, Middle Cambrian, Wheeler formation, Antelope Springs, 

 House Range, Utah. U. S. Nat. Mus., Cat. No. 15453. 



Olenoides curticei Walcott [see Walcott, 1886, plate xxv. fig. 7). 



8. Outlines from nearly an entire specimen that has central portions of segments of thorax filled in from 



another specimen. Note pleural grooves on segment and compare with fig. 7. Natural size. 



From Locality 90 x. Middle Cambrian, Conasauga shale, at Cedar Bluff, Cherokee County, 



Alabama. U. S. Nat. Mus., Cat. No. 58534. 



80. Associated free cheek. Natural size. U. S. Nat. Mus., Cat. No. 58535. 

 86. Fragment of cephalon and thorax, showing free cheek in place and the nodes deflecting inner end 



of pleural groove forward so as to make groove almost oblique. Natural size. U. S. Nat. 



Mus., Cat. No. 58536. 

 Sc. A very well-preserved pygidium associated with the other specimens illustrated. Natural size. 



U. S. Nat. Mus., Cat. No. 58537. 



The species of Olenoides from the Middle Cambrian beds of the Coosa Valley, Alabama, United States, 

 is illustrated to show the differences between Olenoides and Dorypyge. 



