157- 



onyms of Sp. disjunctiis in his monograph. Thus it is certain that at least 

 the Chinese form is different from Sp. disjuiictus of Da\vidson's circumscrip- 

 tion, although the relations between the former and Sp. mjirchisoniana of 

 De Koninck are not very clear. As to this point Hall expresses a similar 

 opinion : " it appears to me that the species figured in the Geology of Russia 

 (i.e. Spirifcr Murchisoniana De Koninck) is distinct from the Chinese speci- 

 mens figured by Mr. Davidson." Davidson himself gives no explanation at 

 all about the relations between these forms in his monograph, and con-- 

 sequently subsequent writers have been quite at a loss. 



Later on, however, it seems that the Chinese fossil first described by 

 Davidson as Cyrtia imtrcliisoniana became the type instead of the prototype 

 of De Koninck. Thus, for example, Kayser, Pellizzari and others give 

 figures of their Cyrtia murchisoniana entirely coincident with those of the 

 Chinese forms in Davidson's paper on Chinese Devonian Brachiopods. 



Now let us turn again to the Uralian fossil described by Tschernyschew 

 as Cyrtia murchisoniana. It differs from the Chinese form, first of all, in the 

 outline of the shell. There is no perforation at all observable on the pseudo- 

 deltidium. It is no way a Cyrtia murchisoniana of Davidson, although it 

 may be comparable with the original Russian species of De Koninck, which 

 is inaccessible to the present writer. If the latter is the case, then it is, in 

 other words, identical with Spirifcr disjunctiis. But Tschernyschew cites 

 the Chinese form of Davidson as well as of Kayser in the synonymy of his 

 Cyrtia murchisoniana. He seems therefore of the opinion that Spirifcr 

 vcrneuili and Cyrtia murchisoniana are identical. Yet in his paper only one 

 oftlie papers concerning Sp. vcincuili ( = Sp. disjunctus) is quoted, and con- 

 sequently it must be concluded that he recognized the distinction between 

 these two forms. Then his classification of the Uralian as Cyrtia vuir- 

 shismiiana must be abandoned if the circumscription of the species by David- - 

 son and others is adopted. 



A similar and rather ambiguous interpretation of the species, under the 

 aame of Cyrtia miircJusoniana De Kon., was repeated quite recently by 

 Loewe. His material, as far as one can judge from the picture, seems to • 

 have been very poor ; it is not very clear how such an excellent diagnosis 



