2l6 RESEARCH IN CHINA. 



A pygidium tentatively referred to this species is illustrated by figure 36, 

 plate 22. It is from Locality (T, Middle Cambrian, lower shale member of the 

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

 and fig. 10 (bed 4), p. 38], 2 miles (3.2 km.) south of Yen-chuang, Sin-t'ai district, 

 Shan-tung, China. 



Collected by Eliot Blackwelder. 



Dolichometopus deois Walcott. 

 Plate 21, Figures 13, 130 d; Plate 22, Figures i, la-h, 2, 2a-b. 



Dolichometopus deois WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 94. (Described and dis- 

 cussed as a new species essentially as below.) 



Bathyuriscus asiaticus LORENZ, 1906, Zeitschr. deutsch. geol. Gesellsch., vol. Lvin.pt. 2, p. 73, plate v, 

 figs. 1-5. (Species characterized and illustrated.) 



Ampholon steinmannl LORENZ, 1906, idem, vol. i.vm. pt. 2, p. 75, plate iv, figs. 1517. (Species 

 characterized and illustrated.) 



This species is represented by the central portions of the cephalon. Glabella 

 and fixed cheeks moderately convex; glabella prominent, moderately convex, and 

 marked by three pairs of rather short, very faintly impressed furrows; the sides of 

 the glabella are subparallel for a short distance near the base and then are gently 

 inclined outward to the rounded front margin; occipital furrow shallow, rounded, 

 and merging into the strong occipital ring ; the latter is narrow at sides, broadening 

 rather rapidly to the base of a small, backward-sloping occipital spine; in front the 

 glabeila curves rather abruptly downward, giving the anterior portion a convex 

 appearance; dorsal furrow shallow and distinctly defined at sides of glabella. 



Fixed cheeks narrow, slightly convex, and sloping posteriorly downward to an 

 elongate postero -lateral limb ; in front of the palpebral lobe the cheeks slope abruptly 

 down to the frontal limb ; palpebral lobes a little longer than one-third the length of 

 the cephalon ; there does not appear to be any definite palpebral ridge ; the elevated 

 rim of the palpebral lobe approaches closely to the dorsal furrow, where it is merged 

 into the downward slope of the fixed cheek ; frontal limb short and slightly convex. 



Surface apparently smooth under a strong lens in specimens from some localities, 

 while in others it is minutely punctate. This appears to depend somewhat on the 

 character of the matrix and condition of preservation. 



On the anterior portion of a cast of a specimen of the glabella there is indicated 

 a very short fourth furrow close to the antero-lateral angle ; the same specimen also 

 shows what is the frontal limb in other cephala divided into a short frontal limb and 

 a narrow, slightly upturned rim. 



The largest cephalon in the collection has a length of 17 mm. 



This species differs from the type of the genus, D. svecicus Angelin [1854, ed. 

 1878, p. 73], in the greater convexity of the glabella, more convex frontal limb, and 

 other minor details of the glabella and fixed cheeks; from D. dirce [plate 22, fig. 5] 

 it differs in the greater expansion of the glabella in front, and from D. derceto [plate 

 22, fig. 4] in the configuration of the frontal limb. 



Bathyuriscus asiaticus Lorenz [see plate 22, figs. 2, 2a-b] is founded on speci- 

 mens of the cranidium that are more or less flattened by compression. Amphoton 

 steinmanni Lorenz is founded on small, convex cranidia. Both forms are abundantly 

 represented among the specimens of Dolichometopus deois both in Shan-tung and 

 Manchuria. 



Through the courtesy of Doctor Deecke, of the University of Freiburg, I had 

 the opportunity of directly comparing the specimens of Lorenz with the type speci- 

 mens of D. deois. 



