INTERCONTINENTAL RELATIONS OF FAUNAS. 495 



limestone, at the base of the Ithaca group. It is Spirifer Icevis of Hall, 

 which closely resembles Schnur's S. euryglosus ; the other names are syno- 

 nyms or closely related species. 



Amboccelia umbonata, Hall, may be said fairly to represent S. urii, Flem- 

 ing, of the Cuboides zone. This race with slight variation ranges throughout 

 the Devonian, both in America and Europe, and well into the Carboniferous, 

 and occurs in the Tully fauna as Amboccelia umbonata. 



S. bifidus, Roemer, is not represented in the American Devonian. It 

 presents some modifications seen in the later types of our S. mesocostalis, 

 but it belongs to a different race. 



It may be noted here that the bifurcation of the plications of Spirifer and 

 the appearance of plications in the sinus are features continuing from the 

 base of the Devonian to the Carboniferous in Europe. In New York there 

 is a gap from S. arenosus of the Oriskany to the S. disjunctus of the De- 

 vonian, in which no representatives of the race appear. In Iowa 8. ivhit- 

 neyi and S. hungerfordi in a measure fill in the gap. 



Spirifer disjunctus, verneuili, orbelianus, archiaci are names applied to 

 varieties of a common race which appears in the Cuboides zone of Europe, 

 and also below in the middle Devonian. In the New York sections it first 

 appears in the Ithaca and High Point (Naples) faunas, both of them above 

 the Tully limestone; and again later, as S. disjunctus, the most character- 

 istic form of the Chemung fauna. In Iowa S. whitueyi occurs associated 

 with middle Devonian species, as in Europe. 



Athyris concentrica is generally present in the Cuboides zone of Europe, 

 but is apparently wanting in the faunas in America most closely allied. 

 There are representatives of the genus both below and above, but I have not 

 found it in the fauna under consideration. 



Pentamerus galeatus, or brevirostris, or some other species, is occasionally 

 reported for the Cuboides fauna in Europe. With us the species is possibly 

 represented by rare examples, but it is a rare form even in the middle 

 Devonian. 



Productus subaculeatus, Murchison, is represented by the Productella spe- 

 ciosa, Hall, abundant a little higher than the Tully. 



Productus dissimilis, Hall (hallianus, Walcott), shown in figures 8, 9, plate 

 12, is seen in the more eastern sections of Europe. The representatives of 

 this genus akin to the European forms occur after the Tully and not before it 



The Camarophoria formosa, Schnur, is either a distinct species or is rep- 

 resented by our Leiorhynchus mesacostalis of the Ithaca zone. 



Orthis striatula, Schloth., and Orthis eifeliensis, de Vera., are represented 

 by our Orthis txdliensis and followed by Orthis impressa; but in New York 

 have no Hamilton forerunners. 



Rhynchonella pugnus and R. acuminata are frequently reported in middle 

 Devonian faunas of Europe, and in some sections are in the Cuboides fauna. 



