LOWER CRETACEOUS FOSSILS — ETHERIDGE. 239 



oval. Sculpture consisting of strong costaB, bent very slightly- 

 concave forwards on the flanks, and single as far as the line of 

 embracement of the volutions, there dividing into twu or three 

 subordinate costa? forming fasciculi, with here and there single, 

 interpolated, and free costse, all crossing the venter almost at 

 right angles to the plane of the whorls; tubercles wanting. 



Obs. — A large Ammonite measuring fourteen by twelve inches 

 on cross diameters, and three feet six and a half around the cir- 

 cumference (central line of the venter). 



The strong costre, single ou the flanks, usually divide into three 

 subordinate ribs, or there may be two only, at the ventro-lateral 

 or abdominal lines, and then cross the venter. When a costa 

 simply bifurcates, there is always a free interpolated secondary 

 rib. The fasciculation of the costaa, a marked feature of the 

 genus, is here a very pronounced character. In common with 

 other species of Perisphinctes, tubercles are entirely wanting. 



The smaller Ammonite nestling in the umbilical cavity with 

 the Leptomarice may be a young stage of the more mature shell. 



A glance at the beautiful figures by Messrs. Neumayr and 

 Uhlig of the North German Hills Formation Perisphinctes 5 will 

 at once convince the reader how very closely this Queensland 

 fossil approaches to the European. In fact, I quite fail to appre- 

 ciate any difference between the former and P. kayseri, N. and 

 U., other than that of size, and by a less curvature of the costa- 

 on the local shell, which is slightly more than double the size of 

 the European fossil. It appears to be more akin to this species 

 than to the larger P. losseni, JS T . and U. 6 , although even this lias 

 some points of resemblance to the Australian representative of 

 the senus. 



j=> v 



Genus Leptomaria, Deslonchamps, 1865. 



(Bull Soc. Linn. Noruuandie, ix., 1865, p. 423). 



Leptomaria (?), sp, 



(Plate lxviii.) 



Obs. — The close resemblance of these casts to Leptomaria 

 giyantea, J. de C.'Sby. 7 , of the Lower Greensand of England 



r, Neumayr & Uhlig — Palaeontographica, xxvii., 3-6, 1891, pis. xvii.- 

 xxi. 



fi Xeumayr & Uhlig — Loc. cit., pi. xviii. 



7 X<>\verby — Trans. Geol. Soc, (2), iv., p. 339, pi. xiv., fig. 16 ; Stoliczka 

 — Leptomaria, Ciet. Fauna S. India (Pal. Ind.), ii. (Gastropoda), 7-10, 

 IStS, p. 3S6. 



