88 RESEARCH IN CHINA. 



Matherella circe (Walcott). 

 Plate 5, Figure 5. 



Straparollina circe WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 13. (Described and discussed 

 as a new species essentially as below.) 



Shell small, hemispherical, spire depressed and rounded in outline ; whorls prob- 

 ably about three; only two are preserved; suture shallow; the whorls are gently 

 and uniformly rounded from the suture down to the more rapid curve to the basal 

 side; as far as can be determined a section of the outer whorl has the form of an 

 ellipse, the narrower parts toward the dorsal furrow and the outer basal margin. 



The surface is marked by concentric, elevated lines that extend obliquely back- 

 ward from the dorsal furrow to the base of the whorl, where they are concealed by 

 the matrix. 



The greatest diameter of the type and only specimen is 3.5 mm.; greatest 

 diameter near aperture, 2 mm.; diameter of whorl opposite aperture, 1.5 mm. 



This species differs from Straparollina remota Billings 1 in the more rapid expan- 

 sion of the outer whorl and more elevated spire and in having a sinistrally coiled shell. 



Formation and Locality. Upper Cambrian: (C 50) Lower part of Ch'au-mi-tien 

 limestone, 25 feet (7.5 m.) below the top of Pagoda Hill [Blackwelder, 19070, p. 42 

 (part of last list of fossils)], i mile (1.6 km.) west of Tsi-nan, Shan-tung, China. 



Collected by Eliot Blackwelder and Li San. 



Genus STRAPAROLLINA Billings. 



Straparollina sp. undt. Walcott. 



Plate 5, Figure 6. 



Straparollina sp. undt. WALCOTT, 1905, Proc. U.S. Nat. Mus., vol.xxix, p. 13. (Species discussed as 

 below.) 



This form is represented by the lower portion of a single whorl, that is rounded 

 in outline and suggestive of Straparollina remota Billings [1872, p. 471]. The 

 greatest diameter across the volution is 6.5 mm., and of the whorl, 2.5 to 3 mm. 



Formation and Locality. Middle Cambrian: (C55) Just below the Ch'au-mi- 

 tien limestone in the Ku-shan shales [Blackwelder, 19070, p. 43], in isolated hills 

 at an elevation of 380 feet (114 m.) above the Won-ho, 12 miles (19 km.) south 80 

 east of Tsi-nan, Shan-tung, China. 



Collected by Bailey Willis and Eliot Blackwelder. 



Genus PELAGIELLA Matthew. 



Pelagiella chronus (Walcott). 

 Plate 5, Figures 9, ga-l>. 



Platyceras chronus WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 14. (Described and discussed 

 as a new species essentially as below.) 



Shell minute, consisting of two whorls somewhat irregularly incurved, the inner 

 whorl being on the plane of the dorsal (outer) side ; the outer whorl expands rapidly 

 toward the aperture, increasing more on the right ventral (inner) side; a cross- 

 section of the outer whorl shows the outer side to be slightly convex and the inner 

 side strongly convex, a rather sharp dorsal angle being formed where the two unite 

 on the outer side. 



'Canadian Naturalist and Geologist, vol. vi, 1872, p. 471, fig. 7. 



