L. F. Spath — On Schlotheimia Greenoughi. 101 



Be la Beche's 1 mention of the form (he alters the name to 

 A. Greenovii) from the Lower Oolite of Bayeux, and a diagrammatic 

 figure of it published by T. Brown, 2 were equally unfortunate, and 

 Blake 3 apparently confused Sowerby's Ammonite with oxynoticerates 

 of Salisburgense type, since he records two specimens of it from the 

 oxynotum zone of . Yorkshire, though he says that one specimen, 

 doubtfully identified with it, occurred in the BucMandi beds near 

 Bedcar. But it is chiefly on Wright's authority that more recent 

 writers, including Hyatt 4 and Pompeckj, 5 put A. Greenoughi with or 

 near Oxynoticeras guibalianum, d'Orbigny, sp., and into the oxynotum 

 zone. 6 Pompeckj, who, as has already been pointed out, is not 

 satisfied about Wright's interpretation of the species, mentions that 

 0. Greenoughi is also quoted from the .BucMandi zone of England, 

 "or more correctly the subzone of Ariet. semicostatum = su\)z(me of 

 Ariet. geometricus or of Pentacrinus tuber 'culatus" In fact, in 

 Somerset (at Bath, Keynsham, etc.), whence probably all the known 

 specimens came and whence the species is recorded by Lonsdale 7 and 

 Morris," it is associated with Vermiceras and Coroniceras, and therefore 

 belongs to the rotiforme or Lower BucMandi zone and not to the 

 geometrician or Upper BucMandi zone. 



With regard to the other forms of Schlotheimia that occur in the 

 BucMandi zone, the dimensions are given below of three large 

 examples quoted by Pompeckj 9 — 



Diameter. Height. Thickness. Umbilicus. 

 Schlotheimia Charmassei, d'Orbigny, mm. percent percent percent 



Pompeckj ( — A. angulatus com- 



pressus, Quenstedt, ii, 2, 1883) . 149 46 24 24 



Schl. intermedia, Pompeckj (= A. 



angulatus intermedins gigas, 



Quenst., pi. iv, fig. 1, 1883) . 600 38 18 32 



Schl.oV Orbignijana (Hyatt), Pompeckj 



( = A. angulatus compressus gigas, 



Quenst., pi. iv, fig. 2, 1883) . . 420 48 18 21 



1 H. de la Beche, " On the Geology of Part of France " : Trans. Geol. Soc, 

 ser. II, vol. i, p. 80, 1822. 



2 T. Brown, Illus. Foss. Conch., etc., 1849, p. 12, pi. ix, figs. 7, 8. 



3 In E. Tate & J. F. Blake, Yorkshire Lias, 1876, p. 296. 



4 A. Hyatt, "Genesis of the Arietidae " : Smithsonian Contributions to 

 Knowledge, 1889, p. 218. 



5 J. F. Pompeckj, op. cit., p. 264. 



6 E. Bose, however, had pointed out in 1894 (" Fleckenmergel " : Zeitschr. 

 Deutsch. Geol. Ges., vol. xlvi, p. 747) that A. guibalianus, d'Orbigny, sp., 

 and A. Greenoughi, J. Sowerby, could not be united as tbey were by Hyatt, 

 since the ribbing was quite different " if one could judge at all from the bad 

 original figure ". We have seen already that Sowerby's figure was for his time 

 very good, but authors, unfortunately, do not seem to have consulted the text. 

 On p. 70 Sowerby also made the important remark (which apparently had quite 

 escaped attention) that A. Comjbeari and A. Greenoughi were generally 

 companions in the same stratum, and were occasionally impressed with each 

 other's type. 



7 W. Lonsdale, Trans. Geol. Soc, ser. II, vol. iii, p. 272, 1832. 

 s J. Morris, Cat. Brit. Foss., 1843, p. 173. 



9 J. F. Pompeckj, Beitrdge z. e. Revision der Amnion. Schtvab. Jura, pt. i, 

 pp. 81-3, 1893. 



