1904 - 5 .] Gr apt olit e-bearing Rocks of the South Orkneys. 469 
Note by Dr Peach on Specimens from the South Orkneys. 
Two specimens of black shale, Nos. 014 and 015, from the South 
Orkneys, have been submitted to me by Dr Pirie for examination. 
No. 015. — In addition to some stipes of graptolite, determined 
by Miss Elies to belong to the genus Pleurograptus, there occurs 
a fragment of another organism, showing a web of dark carbon- 
aceous matter, with a succession of sub-parallel ridges which appears 
to belong to a Phyllocarid crustacean, probably nearly allied to 
Discinocaris. 
No. 014 shows the remains of what appears to have been 
another form of Phyllocarid crustacean, preserved in a dark shining 
anthracitic substance. What seems to be the carapace is broad 
and smooth, with faint indications of raised lines directed outwards 
and forwards on the left side. Where the supposed carapace 
has broken away in splitting the shale, a succession of bands about 
J inch broad, and numbering six within about the same breadth 
backwards, may be observed. These are each ornamented with 
sub-parallel lines and with broadened posterior margins. Both the 
carapace and the apparent body segments are abruptly truncated 
posteriorly in the breaking of the shale. 
A wide experience of the black graptolite-shales of the Southern 
Uplands of Scotland and North Wales, of all horizons, from the 
Lowest Arenig up to the Wenlock and Ludlow rocks, has shown 
that, with the exception of a few small hingeless brachiopods and 
some glass-rope sponges, only the tests of chitinous Phyllocarid 
crustaceans have been met with. Of these, the genus Caryocaris 
characterises the Arenig, Pinnocaris the Lowest Hartfell shales 
(Caradoc), Discinocaris and Peltocaris the Lower Birkhill shales 
(Lower Llandovery), and Aptychopsis and Geratiocaris (the Wenlock) 
dark graptolitic shales. 
The general style of ornament found in the test of most of the 
above genera is that of the sub-parallel raised lines, which may be 
arranged on the carapaces almost concentrically to rudely simulate 
lines of growth in some forms ; but in Ceratiocaris they run longi- 
tudinally backwards. On specimen 015 there appears to be a slight 
curve in the raised lines similar to what occurs in Discinocaris 
gigas, Jones and Woodward, and figured in their monograph. 
