328 NATURAL SCIENCE. May. 



between species, or examples of discontinuous curves of error within 

 the limits of one species, may be due merely to the fact that we 

 are totally unacquainted with the ancestors of the individuals in 

 question. 



Faunal Sequence in Europe and South America. 



In recent numbers we have had something to say about the 

 correlation of geological horizons in different parts of the world 

 (vol. iii., p. 404, and vol. iv., p. 8). In this connection, a paper by 

 Mr. W. Moricke on fossils from the Lias and Inferior Oolite of Chili 

 {Neiies Jahvhuch fur Min., Beilageband ix., 1894) proves of con- 

 siderable interest. It is astonishing to see how many species are 

 considered to be identical with those of Europe, and still more so to 

 see how the European succession is paralleled on the other side of the 

 globe. Thus, a Lower Lias fauna is indicated by Arietites cf. rotiformis, 

 Spiriferina rostrata, Terebratula perforata, Piette, Rhynchonella plicatissima 

 and R. belemnitica, Quenst. ; a Middle Lias fauna, by Hildoceras lilli, 

 jEgoceras jamesoni, Deroceras armatum, D. submuticum, etc. ; an Upper 

 Lias fauna by Harpocevas subplanaium, Hildoceras levisoni, H. comense, 

 Pholadomya fidicula, etc. In the Inferior Oolite the exactitude of the 

 correlation seems even more remarkable : the Upper Lias strata "are 

 followed by red, sandy limestones, which correspond to the zone of 

 A. sowerbyi and A. sauzei. Besides Spharoceras sauzei itself, they 

 contain 5. cf. brocchi, S. polyschides, S. polymermn, Hamniatoceras 

 {Sonninia) polyacantJmm, Waagen, etc. . . . These limestones with 

 A. sauzei are overlaid by a reddish-brown iron-shot oolite, several 

 metres thick, which is rich in fossils . . . and yields the following 

 species : — Coeloceras httmphriesianum (d'Orb. non Sow.), C blagdeni 

 (Sow.), Hammatoceras alleoni (Dum.), H. gonionotiivi (Ben.)," etc. 

 These are considered to indicate the Himiphriesianuni-heds. 



It is certainly startling to read of South American species as 

 definitely occurring in the Humphriesianum- or Sauzei-heds, especially 

 when we remember that the latter have only been recognised in this 

 country within the last few years. It is, however, possible to suggest 

 a doubt as to the correctness of all these determinations and 

 correlations. Hammatoceras alleoni and H. gonionotnm, for instance, 

 belong to a decidedly lower horizon in Europe ; while species, as yet 

 unnamed, which might be mistaken for C. humphriesianum or C 

 blagdeni, occur in this country in close association with those 

 Hammatocerata. Moreover, it may not prove safe to trust these 

 identifications too closely; at all events, fig. 4 of plate ii,, which is 

 named Leioceras siihplanatnm (Oppel), shows a specimen differing from 

 that species in numerous points, and rather resembling Grammoceras 

 fallaciosmn, Bayle. 



Apart from these minor doubts, we are fully prepared to learn 

 that the faunal sequence in South America corresponds remarkably 

 with that in Europe. Whether, as a consequence of this, it will be 



