52 C.H.C. BRUNTON 
METHODS 
The shell material on most specimens is thin, somewhat laminar 
in appearance and takes the buff colour of the matrix. In order 
to establish the nature of this shell, slivers from two specimens 
were studied by qualitative energy dispersive x-ray microanalysis 
using scanning electron microscopy in the Department of 
Mineralogy, The Natural History Museum, London. The results 
show a strong dominance of calcium, with no magnesium or 
phosphorus present (Fig. 9). The mineralogy indicates 
dominance of calcium carbonate (lacking magnesium) and the 
lack of phosphate precludes the presence of apatite. The shell is 
not calcophosphatic so articulate brachiopods could have been 
the animals which secreted this shell material. 
It seemed unlikely that more material would become available, 
so it was important to preserve what we had. For this reason only 
two specimens were sectioned in an attempt to determine what 
internal structures were present. However, some internal details 
could also be seen on broken surfaces which cut across 
specimens while the rock was being broken, as well as on 
naturally weathered surfaces cutting across the partial interiors 
of two specimens. 
Careful examination of all specimens under a binocular 
microscope, commonly making drawings using a Wild drawing 
arm, gradually allowed the recognition of some consistent 
features on several specimens, which provided a form of 
orientation. The recognition of the same structures in different 
views and sections has allowed a general picture of the 
morphology of these specimens to be built up. 
Portions of shell from near the apex and the distal regions of 
the cone, and from the supposed dorsal valve have been studied 
uncoated in the environmental chamber of an ISI ABTS55 
scanning electron microscope and coated using a $2500 Hitachi 
machine, both in The Natural History Museum. 
Fig. 1 Stipulina-like species, ventral valve exterior, BD9673, <4. 
Figs 2,3 Two views of anon-rugose Thomasella-like species. 2, exfoli- 
ated dorsal valve interior and the flanged and geniculated trail, 
BD9677. 3, oblique view of a complete specimen viewed anterolater- oil 
ally showing the strongly ribbed trail, BD9676b, x3. 
Fig.4 Two views of cf. Thomasella showing the posterior rugae, 
flanged trail and ventral spines, BD9673(0), x5. | 
Fig.5 A Plicatiferinid showing the exfoliated dorsal valve interior, 
BD9674, x4. i 
Fig.6 Pectenoproductus ventral valve exterior, BD9675, x2. | 
Fig.7 The incomplete leioproductine ventral valve, BD9688(1), <3. 
Fig.8 Cf. Planispina sp. viewed almost apically, BD9688(0), <1.5. Fig.9 Plot from qualitative energy dispersive X-Ray microanalysis of 
non-coated fragments using scanning electron microscopy. The plot 
displays a major calcium peak (plus a secondary peak to its right), 
but no phosphorus and only minor amounts of elements with lower 
atomic weights, to the left. 
