Vol. 58.] ASSOCIATED BEDS OF THE MALVERN HILLS, 103 
a minute bivalve, Cytheropsis sp. nov., and Spondylobolus (2?) sp. No 
descriptions of these fossils have appeared, and none of them, 
if represented at all in the large collections, are labelled. Their 
identification is therefore a matter of impossibility. A specimen of 
‘ Spondylobolus’ is figured by Phillips’; this is possibly one of the 
species of Acrotreta described in the Appendix to this paper by 
Mr. C. A. Matley (pp. 142 et seqq.). Phillips also recorded and figured 
Olenus pauper, sp. noy., but gave no description of the fossil (doc. cit.). 
The specimen is still in the Museum at Oxford: it is evidently a 
member of the Spherophthalmus-group, and is too imperfect for 
certain determination, but I think that in all probability it is an 
immature Sphwrophthalmus flagellifer.” 
The identification of the Llandeilo species Agnostus Maccoyt, 
Salt., by Phillips (doc. cet.) is in the highest degree uncertain. In all 
probability the species is Agnostus tresectus, which has been confused 
with A. pisiformis, which in its turn was at first confused with 
A, Maccoyi. Great doubt, moreover, attaches to Olenus micrurus and 
O. serratus, both recorded by the Rev. G. E. Mackie.* Murchison 
records also Kutorgina cingulata from the Black Shales.* In all 
probability this name has been accidentally interchanged with that 
of Obolella Saltert, which, though known at the time to occur in the 
Black Shales, does not appear in the list ; while the reverse is the 
case with Autorgina cingulatu.’ It appears, therefore, advisable to 
omit altogether from the list the species enumerated above, especially 
since the precise horizon to which they belong is uncertain, owing 
to the fact that the White-Leaved-Oak Shales and the Bronsil Shales 
have both been included under the name ‘ Black Shales.’ The list of 
fossils, thus amended, obtained from the zone of Sphcerophthalmus and 
its associates may for the present stand as shown on pp. 109, 110. 
The total thickness of the White-Leaved-Oak Shales is probably 
somewhat over 800 feet, of which the olivine-basalts constitute 
perhaps some 300 feet. The zone of Spherophthalmus alatus, with 
some 500 feet of shale, and with 200 feet of basalt, makes up the 
greater part of this thickness. 
ee Geology of Oxford & the Valley of the Thames’ 1871, p. 68. 
2 So far as can be seen, it agrees with this form in the free A cheok and cheek- 
spines ; the glabella, with very good illumination, is seen to be divided by 
furrows arranged much as in this species; the pleurz, with their short deflexed 
spines, also resemble those of Sph. jflagellifer, and the last body-segment seen is 
provided with a dorsal spine; but the number of segments visible in this 
apparently complete specimen is 7, or possibly 8, the first being perhaps 
obscured. 
3 *Malvern Field Handbook’ 1886. 
* *Siluria’ 4th ed. (1867) App. p. 541: sub nom, Obolella Phillipsit. 
° The variety of Kutorgina cingulata recognized as K. Phillipsit must have 
been meant. A different variety, K. pusilla, has recently been obtained by me 
from the Lowest Black Shales (see p. 101). 
