108 RESEARCH IN CHINA. 



lateral angle of the pygidium. The central axis has a length of 10 mm., with a 

 width at the anterior end of 6 mm., and at the posterior terminal lobe of 6 mm., 

 narrowing slightly at the second and third rings; it is divided by three shallow, 

 rounded, transverse furrows into three slightly convex rings and a terminal ring 

 nearly as long as the two posterior rings; there is also a narrow anterior ring that 

 connected the pygidium with the thorax; the terminal ring is convex and slightly 

 overhangs the margin; a node or slight swelling is indicated on each side of the 

 median line where the ring slopes abruptly down to the margin. Dorsal furrow 

 rounded and somewhat irregular. 



Pleural lobes slightly narrower than the axis and arching from the dorsal 

 furrow directly down to the border; the lobes are divided by three broad furrows 

 into an anterior, marginal, elevated rim and two slightly concave segments; a third 

 and posterior segment is indistinctly outlined ; the furrows and segments terminate 

 within a slightly thickened border. Three pairs of short spines occur on the border 

 opposite the two anterior segments and frontal rim of the pleural lobe ; opposite the 

 faintly denned posterior segment there is a long, strong spine, and from the space 

 between the latter spine and where the dorsal furrow intersects the border there is 

 another longer and stronger spine that extends obliquely outward and backward. 



The surface is marked by a few pustules that occur on the elevated portions 

 of the rings of the axis and the pleural lobes ; under a strong lens the crust appears 

 to be slightly roughened and apparently minutely punctate. 



Length of pygidium, n mm.; width at the anterior border, 16 mm.; width of 

 axis, 6 mm.; width of pleural lobe at anterior portion, 5 mm. 



In general outline this pygidium is somewhat like that of Dorypyge richthofeni 

 Dames. It differs in the proportionately broader axis, narrower pleural lobes, and 

 the pair of strong spines at the postero-lateral angle. 



The pygidium of Dorypyge danica Gronwall [1902, plate 3, fig. 12] has two large, 

 long posterior spines on each side next to the axis, also three short spines anterior 

 to the long spines, as in D. bispinosa. The two species are quite unlike in their 

 other characters. 



Formation and Locality. Middle Cambrian: (C2) Lower shale member of 

 the Kiu-lung group [Blackwelder, 19070, pp. 37 and 40 (part of the third list of 

 fossils), and fig. 10 (beds 4 and 5), p. 38], 2 miles (3.2 km.) south of Yen-chuang, 

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



Collected by Eliot Blackwelder. 



Dorypyge richthofeni Dames. 

 Plate 8, Figures i, la-f. 



Dorypyge richthofeni DAMES, 1883, China, Richthofen, vol. iv, p. 24, plate i, figs. 1-6. (Species 

 described and discussed.) 



Doctor Dames gives a detailed description of this species. The new material 

 in the Carnegie Institution of Washington collection shows that the pleural lobes 

 of the thoracic segments have a rounded, straight groove as in Olenoides; also that 

 a spine occurs at the center of the axial lobe, as in Olenoides. 



The specimens described by Doctor Dames were from Ta-ling and Wu-lo-pu. 



In Manchuria the stratigraphic range of this species as now known is confined 

 to the shales and interbedded limestones just above the white quartzite sandstone at 

 the base of the section. 



Formation and Locality. Middle Cambrian : ((' 19) Uppermost layers of the 

 Ch'ang-hia limestone [Blackwelder, 19070, p. 33 (part of last list of fossils), at 



