THE SILURIAN ROCKS OF THE EASTERN MENDIPS. 
79 
probable that this deposit forms part of the course ashy con- 
glomerate mass lying- to the N.E. 
no. This trench was carried to a depth of 5 feet, the last 2\ feet 
being - in coarse ashy conglomerate with the usual tuff matrix. 
The pebbles were mainly of andesite, but one of quartzite was 
met with. 
in. At a depth of 18 inches fine tuff was entered. Here again, as 
at 109, pending further evidence, it seems more probable that this 
is a fine-grained patch in the coarse ashy conglomerate than that it 
indicates the presence of a tuff-band in the Wenlock beds. 
112. This trench w r as carried to a depth of 5 \ feet. The upper 4 feet 
was exceedingly tough red clay. . This passed into yellowish sandy 
clay, clearly disintegrated coarse ashy conglomerate, blocks of 
which were contained in it. 
113. Normal Moon's Hill pyroxene-andesite was entered at a 
depth of 18 inches. 
114. This trench was taken to a depth of 4^ feet, when work was 
stopped by water getting in. The upper 3 feet was tough red clay 
with blocks of Old Red Sandstone, the lower \\ feet was full of 
bits of andesite, which were rather vesicular, an unusual character 
among the Eastern Mendip rocks. It is practically certain that 
andesite is the country rock here. 
115. After penetrating 5 feet of tough red clay andesite was 
struck in situ. 
116. Fresh pyroxene-andesite of Moon's Hill type was entered at 
a depth of about a foot. At this point we have andesite occurring 
within a very few yards of the fossiliferous Wenlock beds of the 
rail-cutting, and still nearer to similar beds exposed by trenching in 
1907. The dip of the fossiliferous beds is such as to show that if 
no fault intervenes they clearly rest on the andesite. The finding of 
andesite at the spots 115 and 116 proves that it extends here con- 
siderably further to the south than was formerly supposed. 
In the British Association Report, Dublin, 1908, p. 287, a list of 
fossils is given which were found in the fine greenish sandy shale or 
mudstone exposed at the spot 92 in a cutting about 600 yards N.E. 
of Long Cross Bottom. The following additions have been made 
to this list, many of the specimens having been collected by mem- 
bers of the Geologists' Association when visiting this exposure in 
June, 1909 : — 
Monticuliporoid 
Or this elegantula Dalm. 
Atrypa reticularis Linn. 
Orbiculoidea rugata Sow. 
Scenidium lewisi Dav. 
Me.ristina tumida Dalm. 
Rhynchonella ( C amarotcechia ) 
borecdis Schloth. 
Ptilodictya lanceolate Goldf. 
Ptilodictya ? scalpellum Lonsd. 
Ctenodonta sp. 
Pterinea retro flexa Wahl. 
Beyrichia klcudeni McCoy. 
Beyrichia sp. 
Phacops ( Dalmanites ) caudatus 
Briinn. (common) 
Phacops musheni Salt. 
Proetus fletcheri Salt. 
Encrinurus punctatus Briinn. 
