322 RESEARCH IN CHINA. 



stand, lio\vever, in a form in which they are broad and faint, like Spirifer ufensis 

 Tschernyschew or, especially, 5. sokolovi Tschernyschew, both of which occur in the 

 S( h\'cigcrina limestone of Russia. The present form, however, is considerably larger 

 than any of the species mentioned. 



Under this title I have associated some imperfect specimens from the same and 

 other localities, much smaller in certain cases but otherwise similar, so far as can 

 be made out. The determination of their real relationship, however, must await 

 the discovery of more complete material. 



Locality and Horizon. Pennsylvania!! (Wu-shan limestone) ; near Ta-ning-hien, 

 East Ssi-ch'uan (stations i and 3). 



Amboccelia sp. aff. A. planiconvexa Shumard. 



Of this species our collection contains but a single specimen, a ventral valve 

 somewhat distorted by compression. From umbo to front the length is 6 mm. 

 The width is about 5 mm. or a little over. The shape is subcircular or subquadrate 

 and the sinus is faint or absent. The surface appears to be smooth and without 

 the scars of spines or other ornament. On this account it has seemed necessary to 

 consider this specimen an Amboccelia, instead of a young example of Squamularia. 

 The generic reference is nevertheless tentative. 



This form, so far as its characters have been ascertained, is very similar to our 

 common American species A. planiconvexa. The only difference which is at all 

 noticeable is the apparent faint development or absence of a sinus; but from a 

 single somewhat crushed specimen the inference that this is a normal feature of the 

 species is hardly justified. 



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

 East Ssi-ch'uan (station 17). 



Martinia ? sp. 



This form is represented by a fragmentary dorsal valve, which probably had a 

 complete length of about 15 mm. and a width of but little less. The shape seems 

 to have been broadly ovate, with rather strong convexity. Two distinct but ill- 

 defined radial depressions divide the surface into three portions, of which the central 

 one, or fold, thus well defined, is perhaps a little broader than the two lateral ones. 



This shell might be a Composita (its exact position is undeterminable) or a 

 member of several related genera, but upon the whole it appears to me rather more 

 probable that it is a Martinia. As such it might belong to any one of a number 

 of species, but too few characters are shown to determine definitely upon this point. 

 So far as can be made out it closely resembles Aihyris globularis as figured by Kayser 

 from Chinese specimens. 



Locality and Horizon. Pennsylvanian (Wu-shan limestone) ; near L,iang-ho- 

 k'ou, East Ssi'-ch'uan (station 7). 



Squamularia ? aff. S. perplexa McChesney. 



This form is represented by five specimens, all from one locality. They are 

 somewhat exfoliated and more or less badly crushed in the black calcareous shale 

 which forms their matrix. While many details can not be made out, resemblance 

 to the common American species 5. perplexa McChesney is rather strong. 



The largest specimen has a length from umbo to front of about 15 mm. The 

 spine-scars are quite large and arranged concentrically in single rows, which are in 

 some specimens rather closely placed but in others are farther apart and separated 



