158 RESEARCH IN CHINA. 
Agraulos nitida Walcott. 
Plate 15, Figures 2, 2a—b. 
Agraulos nitida WALCOTT, 1906, Proc. U.S. Nat. Mus., vol. xxx, p. 576. (Described as a new species 
essentially as below.) 
This species is represented by the central portions of the cephalon, exclusive 
of the free cheeks; the front within the facial sutures is strongly rounded, indicating 
a semicircular outline for the cephalon, which was moderately convex. Glabella 
truncato-conical, moderately convex, and not very clearly defined from the fixed 
cheeks and frontal limb; there are no traces of glabellar furrows; occipital furrow 
represented by a slight depression at the base of the glabella; occipital ring very 
narrow at the sides, thickening rapidly toward the center so as to give it a subtri- 
angular outline, the apex of which terminates in a small spine of unknown length; 
dorsal furrow indicated by the difference in slope of the glabella and fixed cheeks 
and frontal limb. 
Fixed cheeks less than one-half the width of the glabella, nearly flat opposite 
the palpebral lobes, and sloping gently downward to the posterior furrow, and to 
the front to merge into the frontal limb, which is slightly convex; palpebral lobes 
about one-fourth the length of the cephalon. 
Surface slightly roughened by what appears to be a minutely granulated surface 
as shown by a strong lens. 
The largest cephalon in the collection has a length of 5 mm. 
This species is most nearly related to Agraulos dolon [p. 156]. The cephalon 
of the latter differs in being longer in proportion to the width, and in having broader 
fixed cheeks. 
Formation and Locality—Middle Cambrian: (C75) Limestone near the base 
of the Ki-chéu formation [Willis and Blackwelder, 1907, p. 143], 4.5 miles (7.2 km.) 
south of Wu-t’ai-hién, Shan-si, China. 
Collected by Eliot Blackwelder. 
Agraulos obscura Walcott. 
Plate 15, Figure 4. 
Agraulos obscura WALcoTt, 1906, Proc. U.S. Nat. Mus., vol. xxx, p.577. (Described as a new species. ) 
This species is represented by the central portions of the cephalon, exclusive 
of the free cheeks. The glabella and fixed cheeks moderately convex; glabella 
truncato-conical, with the front margin gently curved and antero-lateral angles 
slightly rounded; the postero-lateral angles are more broadly rounded and pass 
into the line of the posterior margin of the occipital ring without interruption by 
the occipital furrow; surface of glabella smooth, with the exception of some very 
slight indications of a posterior pair of furrows; occipital furrow shallow, and 
fading out before reaching the dorsal furrow; occipital ring narrow at the ends, 
broadening and rising toward the center to form the base of what may be a short 
spine, or a slight upward projection of the central portion of the posterior margin 
of the ring; dorsal furrow of medium width and well defined at the sides and front 
of the glabella. 
Fixed cheeks narrow, convex, rising into narrow ridges that anteriorly form 
a node or swelling where they merge into the frontal limb; posteriorly they slope 
down to merge with the postero-lateral limb; palpebral lobes small, somewhat 
elevated, and separated from the fixed cheeks by a shallow furrow; there does not 
appear to be any palpebral ridge; postero-lateral limb about as long as the width of 
the glabella in front; it is marked by a shallow furrow within the slightly rounded 
