RESEARCH IN CHINA. 



Spirifer sp. (b). 

 Plate 29, Figures 6, 7. 



This species is fairly common at certain localities present in our collections, 

 but, the matrix being very hard and tenacious, most of the specimens are exfoliated 

 and fragmentary. On this account, because no part of the material seems fit for 

 figuring, I have refrained from naming what with little doubt is an undescribed 

 species. The following are its characters : 



The size is rather small ; the largest examples probably attained if not exceeded 

 a width of 23 mm. The shape of the dorsal valve is transverse, the proportion of 

 width to length being about as 2 to i . The hinge-line is long, the cardinal extremi- 

 ties pointed, and the configuration in every way as in the common types of the genus. 

 The fold is broad, well defined, but low. It is subdivided by a median sulcus, with 

 the result that the plications upon it are two in number and distinctly larger than 

 the lateral plications. The number of the latter has not been determined, but there 

 were probably ten or more upon each side of the fold. All the plications are rounded. 



The configuration of the ventral valve of course conforms to that of the dorsal. 

 There is a rather broad sinus containing a single median rib. 



The surface is crossed by coarse, strong, radiating lirse, which appear to be 

 somewhat narrower than the intervening channels or striae. A few concentric mark- 

 ings can be made out, but nothing regular or distinct. 



This form resembles in a general way 5. mesicostalis of the Chemung and 

 S. biplicalits, S. niysticensis, and 5. bifurcatus of the Mississippian series of the 

 American section, but is of course specifically distinct from either. In the Upper 

 Carboniferous of North America I know of no analogue. A certain resemblance 

 to 5. strigoplocus of the Russian Carboniferous exists, especially in the superficial 

 adornment, but otherwise there are wide differences. 



From the Silurian of Tshau-tien and other points Kayser has figured a number 

 of Spiriferi related to this which he identifies as Spirifer elcvatus Dalman. They have 

 a very similar expression and in especial agree in possessing a biplicate fold. A 

 constant and significant difference is the greater number of lateral plications in the 

 form under discussion. Kayser does not describe the sculpture of his Chinese shells, 

 but that of European examples differs from our form in possessing concentric as 

 well as radiating lirse. 



Locality and Horizon. Pre-Pennsylvanian (?); near Ta-miau-ssi', Bast Ssi'- 

 ch'uan (stations 6, 8, and 9). 



Spirifer ? sp. 

 Plate 29, Figure 5. 



This form is represented by about 10 specimens, but most of them are frag- 

 mentary. The dorsal valve, nearly complete and fairly well preserved, possesses 

 the following characters: 



The width is 10 mm., the length about 7 mm. The hinge-line is as wide as 

 any part below, the cardinal angles quadrate, and the shape semicircular. The 

 convexity is rather low and the umbo somewhat inflated. There is a low fold, 

 moderately elevated and well defined above, depressed and ill defined below. 



The whole surface is crossed by regular, fine, sharply elevated radii, of which 

 about 7 surmount the fold and about 20 occur on either side. The general appear- 

 ance of this valve is very suggestive of a Chonetes, but it lacks the cardinal spines 

 and the rows of pores or internal pustules found in most Clumcta; between the lira, 

 besides possessing a distinct though low fold. 



