472 BRITISH PAL/ZOZOIC FOSSILS. [Bracuiopopa. 
Position and Locality—Common in the carboniferous limestone of Derbyshire; red carboniferous lime- 
stone of Breedon Hill, Leicestershire ; middle carboniferous limestone, Poolwash, Isle of Man. 
Propucta setosa (Pihill.) 
Ref. and Syn.= Id. id. Phil. Geol. York, t. 8. f. 9 and 17.= P. carbonarius de Koninck, Anim. Foss. Bel. 
t.125 Gis) £1: 
Desc.—Oblong, rounded ; hinge-line equal to the width of the shell, forming flat, nearly rectangular ears, 
abruptly defined nearly at right angles to the sides of the shell, so that they are usually broken off, leaving the 
body of the receiving valve longer than wide. Receiving valve very gibbous, without trace of mesial sinus, sides 
tumid, nearly vertical; visceral portion globose, marked with obscure concentric wrinkles, nearly obsolete in the 
middle, arched to a semicircle with the middle of the front ; beak tumid, projecting very little beyond the hinge- 
line; surface with nearly regular, fine, close, subequal, longitudinal strize (nine or ten in two lines at six lines 
from the beak); spines rather numerous, particularly on the ears and rostral portion, (but also on the front) 
slender, their bases seldom much exceeding the thickness of the striee on which they are placed, and frequently 
producing no interruption in the striation, rather larger towards the margins of old individuals. Entering valve 
deeply inserted, with the visceral portion flattened, concentrically wrinkled, and joining the receiving valve 
about the middle of its front, leaving a large space for the animal; striation as in the receiving valve. Width 
of hinge-line eleven lines, proportional width of sides =, length of receiving valve ;;;, depth of receiving valve {5 
length of visceral disk {%, length of front =, depth of entering valve 4, length of visceral portion 5, length of 
front 3. 
In all the characters of form, proportion and mode of insertion of entering valve, &c. this agrees with the 
young of P. Martini, but I do not believe it ever assumes the long undulated front of that species, and the 
strie are much finer and more regular, and the generality of the spines very small. I have carefully exa- 
mined authentic Belgian specimens of M. de Koninck’s species, and find it perfectly identical in all respects with 
Phillips’s older species ; both the Belgian and British specimens occasionally shew a few spine-bases at the sides 
and near the front margin, as thick as two of the striee, contrasting in this respect with those on the rest of the 
surface, and a row of intermediate size parallel with the hinge-line. 
Position and Locality—Not uncommon in the limestone associated with the coal of Glasgow; dark car- 
boniferous limestone of Craige near Kilmarnock ; and middle carboniferous limestone of Poolwash, Isle of Man; 
dark carboniferous limestone of Berwick-on-Tweed. 
PRODUCTA SPINULOSA (Sov.) 
Ref. and Syn. = 1d.id. Sow. Min. Con. t. 68. f. 3. = P. granulosa Phill. Geol. York. t. 8. f.15 (bad).=P. papillatus 
de Kon. Anim. Foss. Bel. t. 10. f. 6, and t. 12. f. 9. 
Desc.—Transversely broad-oval; front margin even, convex, side margins convex; hinge-line shorter 
than the width of the shell, forming inconspicuous, gradually flattened, obtuse-angled ears. Receiving valve 
moderately and evenly gibbous; beak small, narrowed, incurved to the level of the hinge-line. Entire surface 
covered with subregular, nearly equal, quincuncially arranged, small, prominent, elongate, elliptical spine-bases, 
(usually four or five in the space of two lines, measured transversely, at three lines from the beak) ; in young 
shells, or within four or five lines of the beak, the tubercles are but little longer than wide and about twice their 
thickness apart, but towards the margin of larger specimens they give origin to short obscure ribs (as in P. acu- 
leata), and become rather more crowded. Entering valve deeply and evenly concave, having the surface quin- 
cuncially marked with regular, nearly round pits, twice their diameter apart, representing the tubercles of the 
opposite valve. Average width eight lines, proportional length of hinge-line {5, length %%, length of entering 
valve 7, depth of receiving valve *, depth of entering valve 3. 
The much more numerous, regularly placed, and smaller spine-bases distinguish this species from the 
P. aculeata, as well as the less gibbosity and more transyerse form of the valves. 
