STANTON : THE MARINE CRETACEOUS INVERTEBRATES. 
7 
have described as new may be represented in previous South American 
collections by forms referred to or compared with European species. Be- 
sides searching for similar species in the American Cretaceous faunas, 
comparisons with the Old World faunas have been as careful and com- 
plete as the facilities and time at my command would allow, and in many 
instances related species have been cited, but I do not consider it wise to 
identify a form with a species described from a region thousands of miles 
distant, unless the agreement is so complete as to leave no room for doubt 
as to their identity. Examples of such species that may possibly have 
been thus cited under other names in previous papers are the Ostrea , 
some of the Ammonites, Trigonia subventricosa, and the Tiibiilostmm, all 
of which will be further discussed. 
In recent reviews of the geology and palaeontology of the Argentine Re- 
public by Valentin 1 and Ameghino the data for Mesozoic invertebrates 
are derived almost exclusively from the observations of Steinmann 2 in 
southern Patagonia and the work of Behrendsen 3 on the collections of 
Bodenbender from the western Cordillera between 35 0 and 40° south 
latitude. 
In the neighborhood of Port Famine and the Brunswick peninsula 
Steinmann recognized the Lower Cretaceous, from which Darwin and 
others had obtained a few fossils, to which he added an Inoceramns com- 
pared with /. concentricus . Two degrees north (about latitude 51 0 ) he 
found well-preserved examples of an ammonite of the late Cretaceous 
group of “ Haploceraten,” which was thought to be identical with an 
Indian species, and with it Ananchytes, Gastropods and fossil wood. 
Still farther north between Lake Argentina (near latitude 50°) and Lake 
Rica the Cretaceous was reported to have more sandstones and more fre- 
quent fossils, including Inoceramus labiatus and I. brongniarti , or related 
forms. “From these finds [he states] it is evident that the clay shale 
system of the eastern slope of the Cordillera, whose thickness may be esti- 
mated at not less than 1,000 meters and which forms a broad zone from 
the Strait of Magellan to the lakes of Santa Cruz (perhaps to the latitude 
of Valdivia [40 0 ] ) belongs to the older and later Cretaceous.” 
1 Segundo censo de la Republica Argentina, tomo I, pp. 63-255, Buenos Aires, 1898. 
2 Reisenotizen aus Patagonien, Neues Jahrb. f. Min., 1883, Bd. II, pp. 255, 256. 
3 Zur Geologie des Ostabhanges der Argentinischen Cordillere. Zeitschr. d. Deutsch. Geol. 
Gesellsch. Bd. 43, pp. 369-420; Bd. 44, pp. 1-42, 1891-189 2. 
