TF. H. Rudleston — On the Yorkshire Oolites. 205 



Bien figured (Fig. 9). But the smooth and flowing outline there 

 shown is even more conspicuous. 



Relations and Distribution. — I must confess to a strong suspicion 

 that Act. Scarburgensis is closely related to Act. gigantea, of which it 

 may be regarded as a ventricose variety more or less pronounced. 

 There appears to me to be no specific or even varietal distinction 

 between the Millepore specimen and variety A of the Scarborough 

 fossils. Hence whatever name we give them, they must be regarded 

 as the same species. This serves to show how difficult it is to con- 

 struct a Table of Fossils which shall faithfully represent all the facts 

 of the case. On the whole, setting names altogether on one side, 

 this would seem to be a " deraoid " group, which, except in the 

 matter of size and of relative stoutness, may be regarded as repre- 

 sented in many districts and in more than one horizon. 



89. — AcT^oNiNA TUMiDULA, Morris and Lycett, 1850. PI. V. Fig. 7. 

 1850. ActcBonina tumidula, Morris and Lycett, Gt. Ool. Moll. p. 120, pi. xv. fig. 14. 



Compare — 

 Aclmonina Davoustana, D'Orbigny, Terr. Jurass. ii. p. 169, pi. 286, fig. 5-6. Et. Baj. 



Description. — Specimen from the Scarborough Limestone (zone 3), 

 White Nab. Bean Collection, British Museum. Type refiguked. 

 Spiral angle ? 100°. 



The specimen is, it seems to me, in the condition of a cast peculiar 

 to the Grey Oolite of this locality. The following is the author's 

 description — " Shell small, spire depressed, volutions very narrow, 

 rounded, their sutures deeply depressed : the last whorl gibbous, 

 aperture an elongated oval. This species is shorter than any other 



with which we are acquainted Length 4^ lines, transverse 



diameter 3^ lines." 



Relations and Distribution. — This species was founded on an 

 unique specimen, almost, if not altogether, in the condition of a cast. 

 However, when the test is extremely thin, as in this case, the cast 

 gives the general outline with considerable fidelity. The tumid and 

 ventricose character of the body-whorl seems to connect it with 

 var. B of Act. Scarburgensis, but the spire is altogether more 

 stumpy, and the spiral angle consequently wider ; if, indeed, these 

 indications can be relied upon in a fossil presenting such conditions 

 of preservation. 



I have not seen another specimen in any of the collections. 

 D'Orbigny's species, to which reference is made, is even more 

 ventricose, having a spiral angle of 115°. 



90.— ? AcT^.ONiNA GLABRA, Phillips, 1829. Plate V. Figs. 6, Ga. 



1829, 1835. Aci(eon glaber (Bean MS), Phillips, G.Y. p. 124, pi ix. fig. 3. 



1849. Adaonina glabra, D'Orb. (Phil.J, Prod. i. p. 264, Et. Bnj. 



1850. Actceonina glabra, Phil., Morr. and Lycett, Gt. Ool. Moll. p. 120, 



pi. XV. fig. 10. 

 1875. Actceonma glabra, Phillips, G.Y. 3rd edition, p. 260, pi. ix. fig. 31. 



Bibliography, etc. — The type of Actcenn glaber, Bean, has never 

 been seen by me, but the shell now figured belongs to the Bean 

 Collection and is so described. I have sometimes fancied that these 



