DESCRIPTION OF GENERA AND SPECIES. Ill 



Length of the cephalon, exclusive of the occipital ring, of the type and only 

 specimen, 6 mm., with a width near the edge of the palpebral lobes of 10 mm. 



This species is distinguished from T. typicalis by its broader glabella and fixed 

 cheeks, and upward sloping frontal rim, and from T. Ian si Monke by the absence 

 of a frontal limb and the character of the lobes of the glabella. The pygidia which 

 are referred to T. Ian si may possibly belong to T. alcon ; but from the fact that they 

 are evidently from a different bed of limestone, and that there are no specimens of 

 the cephalon associated with the pygidia, I do not think it best to include them 

 under this species, especially as the cephalon of T. Ian si and the pygidia appear to 

 be from the same bed of limestone. 



Formation and Locality. Middle Cambrian: (C12) Gray limestone near the 

 top of the middle limestone member of the Kiu-lung group [Blackwelder, 19070, 

 pp. 37 and 41 (part of the first list), and fig. 10 (bed 7), p. 38], 3.25 miles (5.2 km.) 

 southwest of Yen-chuang, Sin-t'ai district, Shan-tung, China. 



Collected by Eliot Blackwelder and Li San. 



Teinistion lansi Monke. 

 Plate 9, Figures i, 10 b. 



Teinistion lansi MONKE, 1903, Jahrb. konigl. Preuss. Geol. Landesanstalt und Bergakademie, vol. 

 xxiii, pt. i, p. 117, plate 4, figs. 1-17; plate 9, fig. 3. (Species described and discussed as the 

 genotype of the genus Teinistion.) 



Doctor Monke states that this is the most abundant fossil on the slabs from 

 Yen-tsy-yai. He gives a most elaborate description of the cranidium and free 

 cheeks and portions of thoracic segments and pygidia which he refers to the species. 

 We have reproduced a typical cranidium [fig. i] and free cheek, [fig. ib] for com- 

 parison with Teinistion typicalis [see plate 9, figs. 2, zab]. 



The pygidia referred to this species by Doctor Monke are strongly character- 

 ized, but at the same time they are much like the pygidium named Dicellocephalus? 

 sinensis by M. Bergeron [see plate 8, figs. 4 and 40, of Stephanocare f sinensis 

 (Bergeron)]. The student is referred to the fine illustrations and description of 

 Doctor Monke for further information. 



Formation and Locality. Middle Cambrian: Yen-tsy-yai, Shan-tung, China. 

 Also (C6), thin, platy limestone in the upper shale member of the Kiu-lung group 

 [Blackwelder, 19070, pp. 37 and 41 (second list of fossils), and fig. 10 (bed 12), p. 38], 

 2.5 miles (4 km.) southwest of Yen-chuang, and (C12) gray limestone near the top 

 of the middle limestone member of the Kiu-lung group [idem (part of the first list), 

 and fig. 10 (bed 7), p. 38], 3.25 miles (5.2 km.) southwest of Yen-chuang, Sin-t'ai 

 district, Shan-tung, China. 



Collected by Eliot Blackwelder and Li San. 



Teinistion sodeni Monke. 



Teinistion sodeni MONKE, 1903, Jahrb. konigl. Preuss. Geol. Landcsansalt und Bergakademie, vol. 

 xxiii, pt. i, p. 123, vol. v, figs. 1-4. (Proposed species described and discussed.) 



This species is probably founded on compressed and broken cranidia of Black- 

 iveldcria sinensis Bergeron. 



Teinistion typicalis (Walcott). 

 Plate 9, Figures 2, 20 c. 



Dorypygella typicalis WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 29. (Species described and 

 discussed.) 



Cephalon transversely semicircular, moderately convex. Glabella truncato- 

 conical, with the sides converging gently to the rounded front; three pairs of gla- 



