260 ME. s. s. EUCKMAX OX [voi. Ixxiii^ 



the ^ost-sjyinahtm jyre-falciferum deposits. This was a time of 

 earth-movement and local non-sequences : the full succession — 

 perhaps more elaborate than that to be recorded in the Summary — 

 may possibly be made out b}^ taking note of dissimilar faunas. 



The strata of the Yeovilian, and, locally, even certain beds of 

 the Whitbian, have until comparatively recent times been classed 

 with the Inferior Oolite Series or as Passage Beds between Lias 

 and Oolite — the dividing-line between Lias and Oolites (or Lias and 

 Passage Beds) being roughly taken along the line of change from 

 clay to sand ; but this has been found to vary pala^ontologically b}^ 

 several hemerse.^ Such former association, however, suggests that 

 there may be a more suitable opportunity to discuss these strata in 

 a proposed later communication dealing Avith the faunal sequence- 

 of the Lower Oolites. 



III. DOMERIAX. 



The Scalpa Sandstone, about 240 feet thick, is in the main of 

 Dome^ian date ; some of the base is earlier. There is no direct 

 evidence for the stratigTaphical sequence, but the faunas of the 

 spinatum and mar gar it at us dates are present, with that of alqovi- 

 aiium indicated. There is, however, another remarkable fauna in 

 a* distinctive matrix: it yields Amaltheus Icevis (Quenstedt), in 

 some abundance, some massive Rhj^nchonellids and other brachi- 

 opods. The Amaltheus, a Wiirtemberg species, a ver}' distinct 

 dwarf form, has not hitherto been found in English strata, if my 

 memory serves me truly; the massive Rhynchonellids- are quite 

 new to this country ; the other brachiopods agree in the main 

 with Domerian species of Yorkshire. 



It is suggested, on the principle of dissimilar faunas, that the 

 Scalpa Sandstone shows a new faunal horizon — one ^ost-margari- 

 tatus Y^^t-spinatum — a deposit made during a hemera of Amaltheus 

 Icevis, well-developed and preserved in Raasay, possibly in part, 

 preserved in Yorkshire — it is to be looked for at the junction 

 of the above-mentioned zones — partly, if not entirely, absent froiu 

 the South of England ; but to be found locally on the Continent, 

 possibly in some thickness. 



However, with this addition the sequence of Domerian faunas, 

 is certainly not complete. This is well sliown in a paper by M. J. 

 Monestier.-^ The strata between the Charmouthian and the 

 spiuatum horizon hitherto placed in the zones margaritatits- 

 algovianum (Oppel's upper and lower margaritatus zones) are 

 separated out by him into three subzones, with, in some cases,, 

 further division into uj^per and lower horizons. 



1 'Monogr. Inf. Ool. Amm." (Pal. Soc.) 1890, p. 167. 



2 GrandirhyncMa, S. Buckman, 'Gen. Jur. Brach.' 1914. Two species, 

 figaired in 'Brach. Namyau Beds, Burma' Pal. Ind. n. s. iii (2) 1917 (1918) 

 pi. xiii, figs. 5 & 6, and described on p. 228. 



^ ' Zone k Amaltheus margaritatus ' Bull. Soc. Geol. France, sei*. 4, vol. siii 

 (1913) p. 5. 



