7927 SYSTEMATIC 47 



June 



Rocks of Britain, iv, The Lower Oolitic Rocks of England ; Mem. Geol. 

 Surv., 1894, p. Ill) as proving, in opposition to my statements, the 

 presence of the humphriesianus zone in the Cotteswolds, it being an 

 example of Ammonites humphriesianus recognized by Professor Tate, 

 who said it came from near Stroud. In later years H. B. Woodward 

 most kindly gave me this specimen from Tate's collection. It bears 

 Tate's label " Ammonites humphriesianus, Rodboro'," the well-known 

 locality near Stroud, Gloucestershire. But the matrix shows that Tate 

 must have been wrong in his locality, for it is the unmistakable matrix 

 of the Lower White Ironshot of Dundry, Somerset — a matrix which 

 occurs nowhere else and is quite distinctive. Rodboro' is altogether 

 out of the question. But, even if Tate had been correct in his locality, 

 the specimen would quite fail to prove the presence of the humphriesianus 

 zone in the Cotteswolds, for it is a Sonninian Age form, not a species 

 of the Stepheoceratan { = humphriesianus zone, s.l.). There are no 

 Stepheoceratan strata in the Cotteswolds, and very little of late Sonninian 

 — only at one locality, Cleeve Cloud, near Cheltenham, is there anything 

 later than the date of Witchellia prior to the Parkinsonian (see Table 

 VIII, T.A. V, 74). Tate's specimen is certainly earlier than Witchellia, 

 which equals Upper White Ironshot of Dundry. 



Emileia, S. Buckman, 1898, Jur. Time; Q.J.G.S., liv, 456, "Type 

 Emileia Brocchi (Sow.)." Li comes below guide-line and L2 comes 

 nearly to it. Primary ribs are straight, broadly rounded and club- 

 shaped, without tubercles ; secondary ribs, in large specimens like 

 E. brocchi, are about 5 to i, but in smaller cadicones are only about 

 3 to I. Ribs run nearly straight over a flatly-arched venter. The 

 junction of primaries and secondaries is situated on L2, slightly inside 

 of its median line. 



Emileia shows a remarkable series of species from cadicone to 

 sphseroceratoid to flattened serpenticone. The two extremes are repre- 

 sented by Emileia crater, S.B., T.A. CLXIV, and E. catamorpha, S.B., 

 T.A. CDXIV, so unlike that there would seem to be little connexion 

 between them. But about midway lies E. hrocchii, J. Sowerby, M.C. 

 ecu, large figure. Less robust is Am. brocchi ; Waagen, Geogn.-Pal. 

 Beitr., 1867, iii (r), xxiv, 3. Further advance towards serpenticone is 

 shown by Sphceroceras polyschides ; (Waagen) Greppin, (Bajoc. sup. ; 

 Mem. Soc. Pal. Suisse, 1898, xxv. Pis. i-iii, i, 2), possibly more than one 

 species. More decline is seen in Am. polymertis, Waagen (op. cit, 

 p. 605), name given to Am. brongniarti ; d'Orbigny, cxxxvii, i, 2. 

 Near is Am. brongniarti ; J. Buckman (Amm. I.O. ; Q.J.G.S., xxxvii, 

 1881, p. 64, fig. 5). All these forms which belong to the genus Emileia 

 indicate how E. crater passes to E. catamorpha. 



Also may be noticed Emileia macrocephala, Quenstedt sp. (Amm. 

 Schwab. J. LXiv, 13), a very spheroidal form with small umbilicus — 

 its thickness, at 117, being 74 % or about 20 % more than that of 

 E. brocchii. Am. gervillii grandis, Quenstedt (id., LXiv, 9), appears in 

 proportions to come between E. brocchi and E. polyschides of Greppin, 

 but bears rather heavy primary ribs and a suture-line — incompletely 

 shown — which looks somewhat suspicious ; it is not elaborate enough 

 for Emileia. 



Similar, not sufficiently elaborate suture-lines are shown by forms 

 figured by Gottsche from the Argentine (Geol. Pal. Argent. ; Palseonto- 

 graphica, Sup. iii. Lief. 2, Heft 2, 1878) as Spheeroceras multiforme 

 (Pis. II, III). They have a remarkable likeness in shape to forms of 



