84 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxix. 



traces of glabellar furrows; occipital furrow narrow and rather shallow, 

 rising on the back to the rather strong rounded occipital ring; the 

 latter is broad through the central portions, narrowing at the sides; 

 dorsal furrow rounded and well detined. Fixed cheeks about one-half 

 the width of the glaliella; palpebral lobes small; ocular ridges very 

 faint; frontal limb very narrow, in fact it is ditBcult to decide that 

 the dorsal furrows do not unite with a depressed space in front of the 

 glabella that merges into the frontal furrow; the latter is rounded, 

 shallow, and detines the strong, slightly convex frontal rim; postero- 

 lateral limbs short, marked with a very distinct transverse furrow, 

 just within the posterior margin. 



Surface apparently smooth under a strong lens. 



This species differs from other forms in the very short frontal limb 

 and flattened frontal rim. 



Formation and locality. — Middle Cambrian. Chang Hsia limestone, 

 about 50 feet below the Ku San shale. Chang Hsia, Shangtung, 

 China. 



Collected by Eliot Blackwelder, of the Carnegie Institutiuu of 

 Washington Expedition to China. 



PTYCHOPARIA (LIOSTRACUS) TUTIA, new species. 



Head small, strongly convex; glabella very convex, almost tumid; 

 truncato-conical in outline, and without traces of glabellar furrows; 

 occipital furrow narrow; occipital ring strong and narrow at the sides; 

 none of the specimens show it entire at the center; dorsal furrow 

 narrow and rather deep on the sides of the glabella; not distinctly 

 defined in fi'ont. 



Fixed cheeks about two-thirds of the width of the glal)ella; palpe- 

 bral lobes small, with their posterior end on a line with the longitu- 

 dinal center of the head; ocular ridges narrow but \Qvy clearly defined; 

 frontal limb gently convex, rather short, and ver}" indistinctly sep- 

 arated from the rather broad, almost flattened, frontal rim; postero- 

 lateral limbs strong but short; marked by a strong transverse furrow 

 just within the posterior margin. 



Surface minutely granulose. The largest head in the collection has 

 a length of 4 mm. This very pretty little head is of the general type 

 of Ptychoparia tolus, but it differs in the greater convexity of the 

 glabella and the form of the frontal limb. 



Formation, and locality. — Middle Cambrian. Chang Hsia limestone, 

 central portion. Three and one-fourth miles southwest of Yen Chuang, 

 Hsin Tai, Shangtung, China. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



