NO. 1415. CAMBRIAN FAUNAS OF CHINA— WALCOTT. 83 



(d) broader fixed cheeks, and {e) more broadl}' rounded front to the 

 glabella. The length of the head is 10 ram.; of the glabella, 7 mm.; 

 width of the head including palpebral lobcfs but not free cheeks, 

 12 mm. 



Foruiation and locality.- — Middle Cambrian. Base of Chang Hsia 

 formation in oolitic limestone; 3 miles north-northeast of Hsin Tai, 

 Hsien, Shangtung, China. 



Collected 1\y Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



LIOSTRACUS Angelin, subgenus of PTYCHOPARIA. 

 PTYCHOPARIA (LIOSTRACUS) TOXEUS, new species. 



Of this species only the central portions of the head are known. 

 The glabella and fixed cheeks are rather strongly convex; glabella 

 prominent, truncato-conical, without furrows, except as indicated by 

 a slight darkening of the surface where the furrows usually occur; 

 occipital groove narrow, but very distinct; occipital ring narrow at 

 the sides, rounded, and of medium width at the center; dorsal furrow 

 strong, rounded, and marked by a slight pit at the antero-lateral angle 

 of the glabella. 



Eixed cheeks about one-half the width of the glal)ella at its base; 

 palpebral lobes small and situated about half way between the posterior 

 and front margins; ocular ridges faintly defined. Frontal limb narrow, 

 convex, and sloping downward to a deep, rounded groove which rises 

 in front to a strong, rounded frontal rim; postero-lateral limbs about 

 one-third longer than the width of the fixed cheeks, a strong furrow- 

 extends the entire distance within the posterior margin. 



The surface under a strong lens appears to be smooth. The largest 

 head has a length of 6 mm. with a width of 7 mm. at the palpebral 

 lobes, exclusive of the free cheeks. 



This species may be compared with PtycJioparui oireni^ a form that 

 has a wide geographic distribution in the United States, and also 

 ranges from the Middle Cam])rian into the Upper Cambrian of the 

 Eureka district in Nevada." 



Formation and locality.— M\<\.d\Q Caml)rian. Chang Hsia formation 

 in the basal layers just above the shales; a mile east-southeast of Chang 

 Hsia, Shangtung, China. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



PTYCHOPARIA (LIOSTRACUS) TROGUS, new species. 



Head small, transversely quadrilateral, exclusive of the free cheeks; 

 moderately convex; glabella broadly truncato-conical and without 



«Mon. U. S. Geol. Surv., No. 8, 1884, p. 55. 



