ON LIFE-ZONES IN THE BRITISH CARBONIFEROUS ROCKS. 175 
in the South Wales and Bristol areas should afford grounds for hope that it 
would give a clue to life-zones in the Carboniferous Limestone of the Mid- 
lands. But there are enormous difticulties, and at present, though I hope 
that the corals may give some help, there is no doubt that, as I stated 
last year, Brachiopods which indicate distinct zones, at Bristol seem to 
appear with strange companions in the Midlands. 
The fauna of the Carboniferous Limestone of the Bristol area is com- 
paratively meagre. No Cephalopods, and at most only some half-dozen 
species of Lamellibranchs and Gasteropods, occur in the Bristol-Mendip 
area, and the number of species of Brachiopoda is much less than is found 
in the Midlands. Conditions of life in the two areas must have been 
totally different. 
Dr. Vaughan and I hope to attack the Midland area in the near 
future, and with a type district as a basis of comparison we hope to work 
out a faunal succession. But the task will be immense. There is no 
complete section of the limestones in the Midlands comparable to that 
which occurs at Burrington Coomb and the Avon Gorge, and it is probable 
that not a very great thickness of the limestone of Derbyshire is exposed, 
because I am not acquainted with the fauna of the lower beds of the 
Bristol succession in the Midlands. To do the work thoroughly it will be 
necessary to revise the whole of the species of Brachiopoda, and to spend 
much money and time on sectioning corals ; it will be also necessary 
to collect very carefully, and for this purpose a renewed grant will be 
required. 
Dr. F. A. Bather sends me the following note: ‘I have examined 
and attempted to identify various specimens submitted to me by Dr. 
Arthur Vaughan and other workers. From my point of view, the most 
interesting fact I have to record is the occurrence of the genus Acrocrinus 
in the Bristol area. This genus, which is a very specialised descendant of 
Platycrinide, has hitherto been known only in North America, where it 
is found in the Later Carboniferous. Its discovery by Dr. Vaughan in his 
Zaphrentis zone near Bristol is, therefore, remarkable as regards distribu- 
tion in both time and space. The specimen, though fragmentary, is 
unmistakable, and I propose to publish a description of it before very long. 
Meanwhile, those who wish to know what the genus looks like may be 
referred to a reconstruction given on page 159 of the Echinoderm volume 
of Lankester’s ‘ Treatise on Zoology.”’ 
When collecting in the Pendle Hill district in 1901, Mr. D. Tait 
found a peculiar fossil, which he at once recognised as some form of 
Graptolite! Next year he obtained at about the same horizon, at Pool- 
vash, Isle of Man, another form of a somewhat similar organism. After 
some discussion I referred these fossils to Dictyonema, and drew up a 
brief account, which I read before the Geological Society, March 25, 
1903, entitled ‘Note on some Dictyonema-like Organisms from the 
Pendleside Series of Pendle Hill and Poolvash.’ The paper was not 
published. 
Subsequently I placed the fossils in Miss G. Elles’s hands, and she 
writes me: ‘I think the specimens from Poolvash and Hook Cliff are 
Dendroid Graptolites, without a doubt. The Poolvash specimen looks 
like a Desnograptus, and the other is a Callograptus, I think. The 
Desnograptus is more spread out than in other specimens known to me, 
and is probably new, but the Callograptus has some very near allies in 
C. Salteri and C. radiatus of the older rocks. The presence of the 
