DESCRIPTION OF GENERA AND SPECIES. 131 
three pairs of short, well-defined furrows that divide the sides of the glabella into 
four subequal lobes; an occipital spine and a narrow, rounded frontal rim, cut 
around in front nearly to the median line by the facial sutures. Palpebral ridge 
well defined. Surface unknown. 
Formation and Locality —lLower Cambrian: (C20) Central part of the Man-t’o 
shale formation [Blackwelder, 1907a, p. 26 (last list of fossils), and fig. 6 (bed 14), 
p. 25], on the west side of an isolated butte 1 mile (1.6 km.) south of Ch’ang-hia; 
also (C17), ferruginous limestone nodules in the brown sandy shales at the top of 
the Man-t’o shale [idem, p. 27 (list of fossils at top of page), and fig. 6 (bed 15), p. 25], 
and (C31) gray crystalline limestone in the central portion of the Man-t’o shales 
lidem, p. 26 (first list of fossils), and fig. 6 (bed 12), p. 25], both at Ch’ang-hia, 
Shan-tung, China. 
Collected by Eliot Blackwelder. 
Ptychoparia granosa Walcott. 
Plate 12, Figure 7. 
Ptychoparia granulosa WALCOTT, 1905, Proc. U.S. Nat. Mus., vol. xx1x, p. 78. (Species described as 
below. This species is believed to be congeneric with Hall and Whitefield’s species; since the 
name granulosa is therefore preoccupied for Ptychoparia, granosa is proposed.) 
Not Crepicephalus (Loganellus) granulosus HALL, and WHITEFIELD, 1877, Geol. Expl. Fortieth Parallel, 
vol. Iv, p. 214, plate 2, figs. 2 and 3. 
Ptychoparia granosa WALCOTT, 1911, Smithsonian Misc. Coll., vol. 57, No. 4, pp. 77-78, plate 14, fig. 8. 
(Species described and discussed essentially as below.) 
The gently convex central portions of the cephalon, exclusive of the free 
cheeks, are all that is known of this species. ‘These indicate a rather broad, semi- 
circular cephalon, with small free cheeks, wide fixed cheeks, narrow, short, convex 
glabella, and narrow, flattened frontal rim; glabella marked by three pairs of faintly 
impressed but clear glabellar furrows; frontal space between the glabella and rim 
broader than the frontal rim and slightly convex; palpebral ridge narrow, clearly 
defined, and merging into a rather small eye-lobe. 
Surface slightly granulose. 
Formation and Locality —Lower Cambrian: (C17) Ferruginous limestone nodules 
in the brown sandy shales at the top of the Man-t’o shale [Blackwelder, 19074, p. 27 
(list of fossils at top of page), and fig. 6 (bed 15), p. 25], at Ch’ang-hia, Shan-tung, 
China. 
Collected by Eliot Blackwelder. 
Ptychoparia impar Walcott. 
Plate 12, Figures 9, 9a. 
Ptychoparia impar WaLcort, 1905, Proc. U. 8. Nat. Mus., vol. xxx, p. 78. (Characterized as a new 
species. ) 
This species is represented by many fine specimens of the rather convex central 
portions of the head. ‘The form of the parts preserved is not unlike that of Ptycho- 
paria aclis [p. 130]. They differ in being stronger and more convex, in the absence 
of an occipital spine, and the presence of rather faint glabellar furrows. Palpebral 
ridge rounded and rather strong. 
Surface finely punctate. 
Formation and locality——lower Cambrian: (C17) Ferruginous limestone nod- 
ules in the brown sandy shales at the top of the Man-t’o shale |Blackwelder, 19074, 
p. 27 (list of fossils at top of page), and fig. 6 (bed 15), p. 25], at Ch’ang-hia, Shan- 
tung, China. 
Collected by Eliot Blackwelder. 
