270 PATAGONIAN EXPEDITIONS I PALEONTOLOGY. 



Cucullaria tridcntata (= Cucullaa darwini). Natica solida (= N. darwini). 



Area patagonica. Struthiolaris ameghinai. 



Pecten centralis (= P. prciimus). Marginella quemadensis. 



Lucina promaucana. Marginella confinis. 



Amathusia angulata. Marginella gracilior. 



Dosinia meridionalis. Marginella plicifera. 



Scalaria rugulosa. Valuta ameghinoi. 



Of the 1 1 7 species found at the type-locality of Santa Cruz (see our 

 list, p. 266 f.) the following are mentioned in v. Ihering's list of character- 

 istic Patagonian fossils : 



Cucullcea alta. Lucina ortmanni. Dosinia Iceviuscula. 



Pecten geminatus. Cardium puelchum. Strnthiolaria ornata. 



Cardita incequalis. Venus patagonica. Siphonalia domeykoana. 



These are nine species (all of those mentioned by v. Ihering), eight of 

 which also occur in our collections, only Venus patagonica not being rep- 

 resented. 



On the other hand, of v. Ihering's characteristic Suprapatagonian fossils 

 the following have been found at Santa Cruz, according to our collection : 



Cucullcea darwini. Amathusia angulata. Struthiolaria ameghinoi. 



Area patagonica. Dosinia meridionalis. Marginella gracilior. 



Pecten proximus. Scalaria rugulosa. Marginella plicifera. 



Lucina promaucana. Natica darwini. 



That is to say, all the characteristic Suprapatagonian species, with only 

 three exceptions (Marginella quemadensis and confinis , Valuta ameghinoi'] 

 have been found here. 



This result shows at a glance, that v. Ihering's list of characteristic fos- 

 sils for both supposed formations does not hold good. 



Comparing Ameghino's characteristic fossils with our list of the Santa 

 Cruz fauna we find the following species represented there : 



Jtdiense species : 



4 out of 9. 



Schisaster ameghinoi. 

 Terebratella patagonica. 

 Pecten prcenunchts. 

 Pecten geminatus. 



