306 RESEARCH IN CHINA. 



The foregoing partial description is based altogether upon the external appear- 

 ance of the specimen. The fragment is so small and the preservation of minute 

 structure at this horizon so imperfect that it did not seem advisable to make thin 

 sections. The internal structure therefore remains unknown, and while the general 

 appearance suggests a member of the genus Tceniodictya, it is quite possible that this 

 will not prove its true position. 



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

 ch'uan (station 8). 



Fenestella sp. (a). 



This type is represented by two specimens, only one of which retains sufficient 

 character to furnish data for a description, and upon it the following partial account 

 is based. Only a portion of the frond is preserved, and the non-celliferous face is 

 shown. 



The growth is regular, the branches are nearly parallel, and the introduction 

 of new ones takes place at long intervals. In a longitudinal direction about six 

 fenestrules occur in a distance of 5 mm., while transversely there are nine or ten. 

 The fenestrules are subquadrate, from one and a half to two times as long as wide. 

 The branches are about two-thirds as wide as the fenestrules, and the dissepiments 

 are essentially the same size as the branches. The surface is marked by fine, some- 

 what crowded, rounded, wavy, probably inosculating lirae. 



Characters of the celliferous face not ascertained. 



Locality and Horizon. Pre-Pennsylvanian (?); near Ta-miau-ssi, East Ss'i- 

 ch'uan (station 9). 



Fenestella sp. (6). 



A single specimen represents this type, but it is too ill preserved to be described 

 or to serve satisfactorily for comparisons, and it has been discriminated from the 

 foregoing chiefly because the mesh appears to be somewhat finer. 



Locality and Horizon. Pre-Pennsylvanian ( ?) ; near Ta-miau-ss'i, East Ssi- 

 ch'uan_(station 9). 



Dalmanella ? sp. 

 Plate 29, Figures 3, 4. 



This is a very small species, and, because of the hard, siliceous character of the 

 closely adhering matrix, one rather difficult to study, in spite of its relative abun- 

 dance. No specimen in the collection which can be referred here has a length of 

 over 6 mm., which appears to be about the maximum reached in this dimension. 

 The transverse diameter is usually a little greater. 



The ventral valve is rather strongly convex. In a longitudinal direction the 

 curvature is regular, but transversely considered the greatest flexure occurs medially, 

 so that often a sort of angulation takes place down the center of the shell, the sides 

 being gently convex. The beak is strongly incurved, but projects considerably 

 beyond the well-marked cardinal slopes. The general outline is therefore often 

 somewhat shield-shaped, sometimes subcircular. 



The surface is marked by fine, rounded, very distinct radiating lirse, of which, 

 in a specimen 5 mm. long, there are thirty-four, and this seems to represent about 

 the average, though doubtless more or less variation exists in this particular, appar- 

 ently in the direction of greater fineness. The lirae increase by bifurcation, and 

 certain of them are often irregularly larger than the others. 



