Vol. 58. ] ASSOCIATED BEDS OF THE MALVERN HILLS. 99 
of the series.! Still later this was followed by the researches of 
Belt in the Lingula-Flags of North Wales”; while the subsequent 
investigations of English and Scandinavian geologists have assisted 
in further defining the age of the Black Shales, and have shown that 
they include beds which must be correlated with the Upper Dolgelly 
Beds or upper part of the Lingula-Flags, and represent the zone of 
Spherophthalmus alatus, Boeck, and its associates. 
The Black Shales are found chiefly in the neighbourhood of the 
village of White-Leaved-Oak, and may be termed the White- 
Leaved-Oak Shales. They have been subdivided into the 
following :— 
(4) Upper Black Shales ; 3 
(3) Upper White-Leaved-Oak Igneous Band ; 
(2) Lower Black Shales; and 
(1) Lower White-Leaved-Oak Igneous Band. 
The lowest beds previously recognized are the Lower Black 
Shales. Many years ago a shaft was sunk at the southern end of 
Raggedstone Hill in beds low down in this series.* Symonds, 
regarding these shales as situated on the eastern side of the 
erystalline axis of the hills, stated that they dip steeply away 
from the axis®; this must mean that they have an easterly 
dip, and are therefore presumably inverted, as elsewhere along 
the line of junction with the older rocks of Raggedstone Hill. In 
débris (on the southern side of the road) which, I am informed by 
an inhabitant, was thrown out of this pit, I failed to find any 
fossils, but ‘ Olent’ were obtained from the débris thrown out, 
together with an Agnosius discovered by Strickland.® The latter 
trilobite, at first identified by Salter as Agnostus pisiformis, was 
afterwards separated by him under the name of Agnostus princeps, 
and regarded as a new species allied to the former.’ This supposed 
species, as Mr. Lake and myself endeavour to show on p. 119 of 
this paper, has apparently resulted from a confusion by Salter of 
Agnostus pisiformis with A. trisectus. All the Malvern examples of 
Agnostus from the Black Shales preserved in the collections known 
to us, including an ‘ Agnostus pisiformis’ in the Strickland Col- 
lection at Cambridge, appear to be typical specimens of A. trisectus. 
The shales in question, long supposed to form part of the zone of 
A. pisifornus, therefore belong to the zone of A. trisectus (to which 
Peltura scarabwoides, Spherophthalmus alatus, and Ctenopyge are 
also limited), and, like the overlying portion of the Black Shales, 
must be correlated with the Upper Dolgelly Beds, and not with 
the Lower Lingula-Flags. 
I have, however, detected at another spot beds belonging 
+ «Old Stones’ 2nd ed. (1884) p. 27, 
2 Geol. Mag. 1867, p. 536. 
3 Quart. Journ. Geol. Soc. vol. lv (1899) p. 159. 
4 ‘Old Stones’ 2nd ed. (1884) p. 27; see also[G. H. Piper] Trans. Woolhope 
Nat. Field Club, 1893-94, p. 22. 
5 Old Stones’ 2nd ed. (1884) p. 27. 
° See Murchison’s ‘ Siluria’ 1st ed. (1854) p. 92. 
“ Mem. Geol. Surv. U. K. dec. xi (1864) p. 1. 
