100 L. F. Spoilt — On Schlotheimia Greenoughi. 



The inner whorls of the two larger specimens could not be exposed, 

 and comparison therefore is difficult. But whereas Sowerby's specimen 

 (C) has twenty-eight and nineteen costse respectively on the two last 

 wholly costate (inner) whorls, the specimen figured by Wright has 

 twenty and sixteen respectively, again counting backwards from the 

 last distinct rib shown in the umbilicus. The latter number is the 

 same as in the lectotype ; but Wright's specimen differs both from 

 the latter and from the more closely costate specimen (C) in having 

 more regularly (not excentrically) coiled inner whorls which are 

 coarser and rounder. The outer whorl of Wright's specimen, on the 

 other hand, is flatter and smooth. 



Since neither of the large specimens therefore agrees with the lecto- 

 type, it seems advisable to refer to these forms only as " Schlotheimia 

 spp. ex aff. Greenoughi (Sowerby) ", until duplicate specimens 

 enable us to study their inner whorls and to define their (possibly 

 specific) differences from the lectotype more definitely. What Wright l 

 says about the resemblance of the young to Oxynoticeras guibalianum 

 (d'Orbigny) and the presence of a keel in specimens of from 6 to 

 8 inches in diameter is, of course, erroneous. Sowerby had stated 

 that the "undulations are continued and rather strongest over the 

 rounding back", and though in his figure that author did not give 

 quite the correct course of the radial line, the above remark obviously 

 did not point to connexion with Oxynoticeras. Wright here followed 

 previous authors, especially von Hauer, whose A. Greenoughi? like 

 that figured by Parona, 3 has now been included in Fucini's Oxynoti- 

 ceras Haueri} Sowerby's Ammonite, unfortunately, has been 

 misinterpreted by Continental writers since the time of von Buch. 

 That author figured as A. Greenoughii 5 an Ammonite that Quenstedt 6 

 thought might be the same as A. Tessonianus of d'Orbigny from the 

 iron-oolite 8 (i.e. loitchellia zone of the Inferior Oolite), and Giebel 7 

 mentions that Graf Miinster records it from the Oxford Clay. 

 Studer 8 has it from the Upper Lias (Toarcian), and Ooster's 

 A. Greenoughi* again is, according to Hug, 1P an Oxynoticeras of 

 guibalianum type. Dumortier u also probably misinterpreted the 

 species when he recorded it from the oxynotum zone. 



1 T. Wright, Lias Ammonites, p. 385. 



2 F. v. Hauer, " Uber die Cephalop. aus dem Lias der Nord - Ostlichen 

 Alpen " : Denkschr. Akad. Wiss. Wien. Math.-Naturwiss. Klasse, vol. xi, 

 p. 46, pi. xii, figs. 2-4, 1856. 



3 C. F. Parona, " Ammon. Lias infer. Saltrio " : Mem. Soc. Pal. Suisse, 

 vol. xxiii, p. 18, pi. i, fig. 2, 1896. 



4 A.. Fucini, " Cefal. Lias, del Mte. di Cetona," part i: Pal. Ital., vol. vii, 

 pp. 8-9, 1901. 



5 L. v. Buch, Explication de trois Planches oV Ammonites, 1830, pi. i, 

 figs. 2a-c. 



6 F. A. v. Quenstedt, Handbuch der Petrefaktenkunde, 1852, p. 364. 



7 C. G. Giebel, Fauna der Yorwelt, vol. iii, p. 554, 1852. 



8 B. Studer, Geologie der Schiveiz, vol. ii, p. 36, 1853. 



9 W.-A. Ooster, Cat. Ceph. Foss., vol. vi, p. 45, pi. xvi, figs. 1, 2, 1863. 



10 0. Hug, " Beitr. Kenntn. Lias & Dogger Amm. Freiburger Alpen," II: Abh. 

 Soc. Pal. Suisse, vol.,xxvi, p. 6, 1899. 



11 E. Dumortier, Etudes Paleont. Depots Jurass. Bassin du Rhone," vol. ii, 

 p. 148, 1867.. 



