132 RESEARCH IN CHINA. 



Ptychoparia impar var. ? Walcott. 

 Plate 12, Figure 10. 



Ptyc/wparia impar var. ? WALCOTT, 1905, Proc. U.S. Nat. Mus., vol. xxix, p. 79. (Variety character- 

 ized as below.) 



This variety differs from the type of the species in having more distinctly 

 denned glabellar furrows, slightly narrower frontal rim, and more rounded frontal 

 margin to the glabella. There are several specimens of the cephalon from one 

 locality which appear to vary among themselves as much as some of them vary 

 from P. impar [p. 131]. The latter, and the forms referred to the variety, come from 

 the upper portion of the Man-t'o formation. 



Formation and Locality. Middle Cambrian: (CH) Brown sandstone and lime- 

 stone nodules in brown micaceous shales near the top of the Man-t'o formation 

 [Blackwelder, 19070, fig. 8a (bed 27), p. 29], 3.4 miles (5.4 km.) southwest of Yen- 

 chuang, Sin-t'ai district, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Ptychoparia kochibei Walcott. 



Plate 12, Figures 5, jfl-c. 



Ptychoparia kochibeiVfALCOTT, 1911, Smithsonian Misc. Coll , vol. 57, No. 4, pp. 78-79, plate 14, figs. 

 10 and ion. (Described and discussed as a new species essentially as below.) 



The cephalon of P. kochibei, in outline, wide fixed cheeks, broad frontal limb, 

 and broadly rounded front margin of the glabella, is similar to the cephalon of 

 Ptychoparia granosa Walcott [plate 12, fig. 7]. It differsin having amore pronounced 

 swelling of the frontal limb in front of the glabella, more tumid fixed cheeks, and 

 in surface characters. The surface of P. granosa is thickly studded with minute 

 tubercles, while that of P. kochibei is smooth or possibly finely punctate ; its frontal 

 limb is also marked by fine, irregular, sometimes inosculating, rounded ridges that 

 extend from in front of the glabella and palpebral ridges to the groove within the 

 flattened frontal rim [fig. 56]. 



The thorax has fourteen transverse segments with a narrow axial lobe and wide 

 pleural lobes. The pleural furrow starts on the inner front side of the pleural lobe 

 of each segment and, widening nearly to the width of the segment, begins to narrow 

 at the point of geniculation and terminates near the posterior margin at the some- 

 what abrupt falcate termination of the pleura. 



Pygidium small ; the axial lobe is crossed by two furrows that serve to outline- 

 two transverse rings and a terminal section ; two anchylosed segments are outlined 

 on the pleural lobes on each side of the axial lobe by furrows that curve gently back- 

 ward toward the faintly defined border. 



Surface finely punctate or slightly roughened by minute depressions. 



This is the only Chinese species of Ptychoparia of which we have the entire 

 dorsal shield; all the other species are represented by the separated parts. In 

 outline the dorsal shield is not unlike that of Ptychoparia kingi (Meek) [see Walcott, 

 1886, p. 193], and it may be considered as the Chinese representative of that species. 

 For comparison a photograph of a specimen of P. kingi [fig. 6, plate 12] is given on 

 the plate with the figures of P. kochibei. 



The specific name is given in honor of the former Director of the Geological Sur- 

 vey of Japan, Doctor Kochibe. 



Formation and Locality. Middle Cambrian: (35n,35r, and 36 e), Fu-chou series, 

 limestones and shales interbedded with limestones near the base of the series just 



