CARBONIFEROUS BRACHIOPODA. 
309 
greatest width of the shell ; frontal margin presenting a gentle outward curve. Ventral 
valve very convex and geniculated, with sometimes a slight longitudinal depression along 
the middle. Auricular expansions rather large, flat, and well defined, beak small and 
incurved. Surface of valve ornamented with some thirty small rounded ribs, from which 
project a very few short spines, three or four, also rising above and close to the cardinal 
edge on either side of the beak. About half the number of the ribs are due to shorter 
interpolated ones, and to the occasional bifurcation of a few of the ribs near the 
margin of the valve. The valve is also crossed on its visceral portion or upper part of 
the shell by a few, rather strong, concentric wrinkles. Ventral valve flat, or gently 
concave on its visceral portion, the sides bending upwards rather abruptly. Surface 
ornamented by some thirty ribs, which are crossed by concentric wrinkles as in the 
opposite valve. 
Obs. None of the British specimens showed the characters of the interior of the 
valves, but Prof. L. de Koninck states, in his description of the species, that the internal 
surface is covered with fine granulations, — that the muscular impressions in the ventral 
valve are rather large and of a well-marked oval shape, — and that on the interior surface 
of the dorsal valve the reniform impressions are short. Some Belgian examples have 
slightly exceeded in dimensions those hitherto found in Great Britain. 
Prof, de Koninck observes that M'Coy was acquainted with only a fragment of this 
species, and which is nearly related to P. pUcatilis, but from which it is distinguishable 
by its smaller dimensions, width of its ribs, and the spines close to its cardinal edge. 
He observes also that he found this Produdus in the Lower Carboniferous Limestone 
of Vise, near Liege, in Belgium. 
In Scotland it was discovered by Mr. John Young, of the Hunterian Museum, 
Glasgow, at Brockley, near Lesmahago, in Lanarkshire, and the Scottish specimens have 
been sent to, and identified by, Prof. L. de Koninck with his species. 
40. Proditctus carbonarius, de Kon. Dav., Carb. Mon., p. 160, PI. XXXIV, fig. 6; 
and Sup., PI. XXXVI, figs. 7, 8. 
At p. 160 of my Monograph I described and identified this species from a single 
specimen, said to have been found in Carboniferous Limestone, north of Glasgow (?), 
and I observed at the same time that it would be very desirable that more specimens 
should be obtained before its specific claims be definitely recognised. Since those lines 
were published, Mr. J. Neilson, jun., has been fortunate enough to discover some twelve 
or more specimens in Calcareous Shale and Cement, which Prof. L. de Koninck has seen 
and identified with his species. Those specimens were obtained from a railway-cutting 
at Garngad Road, Glasgow. This interesting discovery was made known to the 
