r 62, 



- 80. 



.121, 



26, 

 23, 



20, 



— , 54. 



16(18), 57. 

 16(17-H), 60. 



r.49, 



27, 



17(21), 51. 



r.68, 

 r.74, 



F.76, 

 S. 62. 



25, 



24, 

 25, 

 23. 



18(20)?, 56. 

 17, 57. 

 17(19), 58. 

 17(21), 57. 



302 ME. s. s. BrcKiiA>' ox [vol. Ixxiii, 



style of reclinate and well-spaced ribbing, Quenstedt's specimen 

 is not, however, quite the same : it is the next step onward ; its 

 smooth stage is evidently shorter, its Avhorl somewhat broader, and 

 its umbilicus rather naiTower. 



For dimensions of this and comparable species, see below. 



History of figured specimen. — Out of a dark (phosphatic?) 

 limestone of the Lower Lias from Paidton, neai' Kadstock (Somerset) 

 — pai'chased from a workman. 



Table XVII. — Peopoetioxs : Ajrxiocefus FomrxAirji and like Foems. 



Arnioceras fortunahim, nor S.-{ 



Arnioceras aff. fortunatum. 



{Ammonites ceratitoides Quenstedt, xiii, 8) ^. 



Arnioceras todleyi (J. Buckman). 



(Ammonites hodleyi J. Biicknian, xi, 7) -... 

 {Arietites semicostatvs Wright, i. 4, 5)^ ... 

 (Aminonites ceratitoides Quenstedt, siii. 10)^ 

 {Arnioceras hodleyi S. Bxickinan) "* 



CoEO^'iCEEAS BrcxLAXDi (J. Sowcrby). 



1816. Ammonites bncl-Jandi J. Sowerby, ' Mineral Concliologv ' vol. ii, pi. cxxx 

 & p. 69. 



Mr. Tutcher has a large specimen from Keynsham, near Bath 

 (Somerset) — a topotype, for Sowerby's "Bath and the neigh- 

 bourhood ' doubtless meant Keynsham. He gives the following 

 proportions, S. -1:93, 26, 32, 55 ; and Sowerby"s figure, allowing for 

 foreshoi-tening, I estimate to give much the same : his figure is 

 presumably reduced to about a Cjuarter of the natui-al size. 



Mos:t interpretations of this species fail to allow for the great 

 thickness of whorl maintained to 20 or more inches in diameter. 

 See Chronological paper, p. 273. 



Family DEROCEEATIDJE. 



Genus Deeoceeas Hyatt. 

 Deeoceeas BisPixiGEErM, nom. nov. (P. 294, fig. 7.) 



1903. Deroceras sp., S. S. Buckman, Q. J. G. S. vol. lix, pi. xxvii, figs. 5 & 6 



(holotype). 

 1914. Bituberculate Deroceratid, Lang, Proc. Gaol. Assoc, vol. xxv, p. 321. . 



Ee marks. — This name is for a species already figm-ed in the 

 Society's Jom-nal but without trivial appellation. As Mr. Lang 

 has now found another example 37 mm. in diameter, with the same 



1 ' Ammoniten d. Schwabisclien Jura.' 



' ' Geology of Cheltenliam ' new ed. 1844. 



3 ' MonogT. Lias Ammonites ' 1878. 



"* Figured in ' Palseontologia Universalis ' 1904. Xo, 36. T^ The end of the 

 whorl, it should be noted with regard to figs. T^''', T^*, is somewhat swollen 

 with pyrites. 



