REPORT ON UPPER PALEOZOIC FOSSILS FROM CHINA. 323 



by bands of fine concentric striae, four or five striae in each band. This may prove 

 a specific or varietal difference among the specimens themselves, which, however, 

 it did not seem wise to enforce here, and it may also constitute a practicable dis- 

 tinction from the American species, in which a similar character is seldom observed. 

 Like the latter, the form under consideration appears to be without septa or dental 

 plates. So far as my observation extends these structures are absent in this group 

 in all species of Upper Carboniferous or Pennsylvanian age, and present in all those 

 which occur in older rocks. This fact appears to me to satisfactorily validate these 

 two divisions as being, if not of generic, at least of subgeneric value, and since 

 McCoy's term Rcticularia was associated with the septate group, though latterly 

 extended to designate both, I have already proposed to restrict it to the original 

 content. For the nonseptate group I have provisionally employed Gemmellaro's 

 term Squamularia, which some European authors, who appear to have examined 

 characteristic examples of that genus, regard as a synonym of Reticularia. Squaiint- 

 luria is unprovided with internal septa, however, and can not, therefore, be the same 

 as Reticularia s. str., and as it is said to be ornamented with continuous projecting 

 lamellae instead of fimbrias of spines, bearing about the same relation to the nonsep- 

 tate Reticulariae that among athyroids Athyris does to Cleiothyridina, it seems a 

 little doubtful to me whether precisely the same term should be employed for both. 

 Locality and Horizon. Pennsylvanian ; near Yen-chuang, Shan-tung (station 69) . 



Cleiothyridina ? sp. 



Two specimens, each from a different locality, represent this group. They 

 possess a general resemblance, but it is far from certain that they belong to the 

 same species. 



A specimen from station 69 is transversely ovate, with a length of 10 mm. and 

 a width of about 12 mm. It is probably imperfect, but the shape appears to have 

 been about as described. The beak is small, pointed, and moderately elevated and 

 incurved. The expression of this little shell is distinctly athyroid, and though the 

 surface characters are unknown, it seems probable that it is a Cleiothyridina. 



The other specimen, which was obtained from station 17 and appears to be a 

 dorsal valve, has a length of 7 mm. and a width slightly greater. It is compressed 

 entirely flat, and the shape is subcircular, the beak being inconspicuous. The sur- 

 face characters have been lost. A fibrous shell structure gives the semblance of 

 very fine striation, in addition to which delicate concentric lines can be made out. 

 This specimen has somewhat the appearance of an Orthis, a resemblance enhanced 

 by the finely striated surface, but its real affinities are probably very different. 



It is not deemed advisable to attempt to determine the specific relations of 

 these specimens from material at hand. 



Locality and Horizon. Pennsylvanian (Wu-shan limestone); Tung-kuan-k'ou, 

 East Ssi'-ch'uan (station 17). Pennsylvanian; near Yen-chuang, Shan-tung (sta- 

 tion 69). 



Dielasma ? sp. 



This is an internal cast of a small ventral valve which is about twice as long 

 as wide and has a length of only 3 mm. The general shape is subelliptical. Two 

 strong dental plates are shown. There can be little doubt that this shell is a tere- 

 bratuloid, the only other type possessing claims of consideration being Composita. 

 So far as I have been able to ascertain, that genus, which is so abundant in American 

 Carboniferous faunas, is exceedingly rare elsewhere, and would hardly be expected 

 to appear in the present geographic and faunal relations. Furthermore, young 

 Composite are usually nearly circular in outline and would hardly have the dental 



