592 PROCEEDTNGS OF THE NATIONAL MUSEUM. vol. xxx. 



the one mentioned above, but differing from it in having a shorter 

 frontal limb, occurs in the upper portion of the Ki-chou limestone, 4 

 miles east of Fang-lan-chon, Shan-si, China. The locality of the head 

 first described is as follows: 



Formation and locality.- -^Vvdd\Q Cambrian, in a brown, oolitic lime- 

 stone near the base of the Ki-chou formation; 4 miles soutii southwest 

 of Tung-yii-chon, Shen-si, China. 



Collected by Eliot Blackwelder. 



PTYCHOPARIA(?) MAIA, new species. 



This species is represented by one fairly good specimen of the central 

 portions of the head, to which the description ot PtycJiojxjria? hrornvK 

 Walcott" applies, with the exception that the latter has broader fixed 

 cheeks and a flatter frontal rim. P-{f) mala also has short, strong 

 ocular ridges that are not present in P.? hroimis. 



The t3'pe specimen of the head has a length of 4.25 mm. 



Formation and locality. — Middle Cambrian, in a brown, oolitic lime- 

 stone near the base of the Ki-ch6u formation; 4 miles south-southwest 

 of Tung-yii-chon, Shen-si, China. 



Collected by Eliot Blackwelder. 



LIOSTRACTJS Angelin, subgenus of PTYCHOPARIA. 

 PTYCHOPARIA ( LIOSTRACUS) INTERMEDIA, new species. 



This is a form intermediate between Ptyvhoparia tolas Walcott* and 

 ]Hychopa7'ia {Liostracus) suhrugosa {p. 592). It is represented by the 

 well preserved central por.ions of the head of a single specimen. It 

 differs from both of the species mentioned by having a i^roportionallv 

 shorter, liroader glabella, with a strong, uniform dorsal furrow about 

 it, and two pairs of less strongly indicated glabellar furrows; also 

 in the detjiils of the fi'ontal limb and rim. 



The surface of PtycAojjaria (Z.) intei'media is marked by a few 

 scattered, rather large tubercles and many very fine tubercles. A 

 head 8 mm. in huigth has a width at the outer edge of the palpel)ral 

 lobes of 9 mm., with a convexity of 2 nun. al)ove the plane of the mar- 

 gin of the head. 



Fornuition and locality. — Middle Cambrian, upper part of oolitic 

 formation; Ch'au-mi-tien, Shan-tung, China. 



Collected by Eliot Blackwelder. 



PTYCHOPARIA (LIOSTRACUS) SUBRUGOSA, new species. 



This species is represented by two specimens of the head, exclusive 

 of the free cheeks. These portions of the head are subrectangular 



«Proc. U. S. Nat. Mua., XXIX, 1905, p. 76. ^Idem, p. 82. 



