Q\WO JBlftStOlbS ( Orophocrinus and Acentrotremites) 
from Somerset. 
By F. A. Bather, M.A., D.Sc, F.R.S. 
(With Plate.) 
(Published by permission of the Trustees of the British Museum). 
rpWO Blastoids, recently found by Mr. J. T. Underhill and Mr. 
1 J. W. Tutcher, of Bristol, and submitted to me for examin- 
ation through the courtesy of the latter gentleman, proved of 
such interest that, through the generosity of their respective 
discoverers, they are to be preserved in the national collection. Mr. 
Tutcher has added to his kindness by preparing some of the illus- 
trations to the present note. 
Orophocrinus orbignyanus (De Koninck). 
(Plate, figs, i and 2.) 
For references to literature see "List of the genera and species 
of Blastoidea," British Museum, 1899. 
The specimen [Brit. Mus. E. 8255] comes from the Tournaisian 
Zaphreittis zone of the Carboniferous Limestone at Waterlip, near 
Shepton Mallet, Somerset. The type-specimen and all other 
known specimens are from the Tournaisian of Tournai. The 
species has not hitherto been found in England, nor has it, so 
far as I am aware, been recorded outside Belgium. 
The specimen consists of a complete theca, lying beside a piece 
of stem on g'rey limestone matrix (Fig. 1). In general shape the 
theca resembles that figured by Etheridge & Carpenter, 1886 
(Cat. Blastoidea, Brit. Mus., pi. xiv. fif. 16, 17), but is rather more 
elongate. The holotype, on the evidence of the original figure 
(1842), is less elongate even than Etheridge & Carpenter's figure, 
and further differs in the concave curvature of its sides. The 
same features are seen in the figures published by De Koninck & 
Le Hon (1854), though the curvature is less marked in their 
enlarged figure 5 b. Since the latter authors said that only one 
complete specimen was known to them, their figures and those 
originally published by De Koninck (1842) must all represent 
that specimen. The holotype was said by De Koninck & Le Hon 
to be at the Ecole des Mines, Paris, and without seeing; it one 
cannot of course say which fig-ure is most correct. The same 
uncertainty attaches to the measurements, which differ from state- 
ment to statement and from figure to figure. The specimen 
figured by Etheridge & Carpenter was said by them to belong to 
the University of Li^ge, and was therefore not the holotype. 
The base of the holotype is described as hollowed and as sub- 
trigonal. The latter feature may be also expressed by saying that 
each basal has a slight keel at its proximal end. Both of these 
features are very faint in the English specimen, and in this 
