s„. 111.=.. CAMBIilAN F.WNAS OF CHINA— WALCOTT. 79 



PTYCHOPARIA IMPAR, variety?. 



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

 distinctly defined glalxdhir furrows, slightly narrower frontal rim. 

 and more rounded frontal margin to the glabella. There are several 

 specimens of the head from one locality, which appear to vary among 

 themselves as much as some of them var}" from P. hiijxir. The latter 

 and the forms referred to the variety come from the upper portion of 

 the Man To formation. 



Format/on. and locality. — Lower Cambrian, upper portion of Man 

 To formation, in shaly sandstone and limestone; Cluing Hsia, Shang- 

 tung, China. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



PTYCHOPARIA LIGEA, new species. 



Head, exclusive of free cheeks, subquadrilateral in outline, mod- 

 eratel}^ convex; glabella almost of the same width from the posterior 

 margin to the rounded front; three pairs of furrows are faintly Init 

 clearly indicated; occipital ring strong; occipital furrow shallow but 

 extended out on the lateral limbs as a strong furrow. Fixed cheeks 

 nearly as wide as the ghibella; palpebral lobes short and small; ocular 

 ridges narrow and strongly detined; frontal liml* slightly convex to 

 where it merges into the broad, shallow furi'ow that extends nearly 

 out to the front margin; posterodateral liml)s rather long. 



Surface slightly roughened by minute, irregular, raised lines that 

 can be seen only with a strong lens. 



Formation and loaditij. — Lower Cambrian. Middle of ]\Ian To 

 formation. Chang Hsia, Shangtung, China. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



PTYCHOPARIA MANTOENSIS, new species. 



Only the central portions of the moderately convex head of this 

 species are detinitel}' known. It is characterized by the l)road frontal 

 space and flat frontal rim; the sides of the glabella converge slightly 

 toward the front margin, which is broadly rounded; glabellar furrows 

 indicated by three very faint depressions on each side. Occipital 

 furrow relatively shallow and rounded; tixed cheeks rather broad; 

 eye lobe occupies the central third of the distance from the posterior 

 margin to the anterior flattened rim; ocular ridges not strongl}^ 

 marked. 



Surface slightly roughened by almost microscopic, irregnilar raised 

 lines. 



An associated free cheek has a long, slender postero-lateral spine. 



