192 
limited by two, rather thiek, rounded lateral folds, on the sides of which are 
three smaller folds. The number of these folds is usually greater than in 
this specimen, and may vary from six to ten ; but, in spite of this variation, 
I have no doubt that it is identical with the species first described by Martin, 
because I have seen it in all its modifications in the Vise Limestone. The 
surface is ornamented with some lines of growth. 
Dimensions. — The specimen I liave just described is only fifteen milli- 
metres long, and about as broad ; it is precisely like that I have figured in 
PI. XV, Pig. and 1®, in my “Descriptions des Animaux Possiles.” 
Horizon and Localities. — This species is generally rare, and belongs to 
the upper beds of the Carboniferous Limestone. It has been found at Buxton, 
Settle, Bolland, and Kirkby-Lonsdale, in England, and at Millecent in Ireland. 
I found it at Vise, and Mr. W. B. Clarke found it in a compact ferruginous 
limestone at Stroud, where it is associated with a large number of fragments of 
Terebratula sacculus, Martin, some of which have preserved their perforated 
structure. 
Spirifeu bisulcattjs, J. Soicerhy} 
PL XIV, Pig. 5. 
A.nomi(2 striatce, Ure, 1793, Hist. EutLerglen, p. 314, pi. 15, fig. 1. 
Terebratula, 1797, Eucycl. Meth., pi. 244, fig. 5. 
S2^irifer trigonalis, J. Sowerby, 1820, Min. Conch., Ill, p. 17, pi. 23, fig. 2, 3 (non W. 
Martin). 
,, bisulcatus, J. de C. Sowerby, 1825, Hid., V, p. 152, pi. 413, fig. 23. 
Spirifera bisulcata, T. Davidson, 1857, Mon, Brit. Garb. Brach., p. 31, pi. 4, fig. 1 ? pi. 5, 
fig. 1, pi. 6, fig. 1-19 and pi. 7, fig. 4. 
Spirifer bisulcatus, L.-G. de Koninck, 1872, Eecb. Anim. Foss., II, p. 61, pi. 2, fig. 6, 7 
(for synonymy). 
Spirifera allied to S. bisulcata, B. Etheridge, Senr., 1873, Quart. Journ. Geol. Soc., 
XXVIII, p. 335, pi. 17, fig. 2. 
This shell, which can attain rather large dimensions, is generally 
broader than long, and oval or subrhomboidal according as its hinge area is 
more or less extensive. Both valves are regularly curved and nearly of the 
' \_Sp'irifera trigonalis, Martin, var. hisulccvta, J. de C. Sby. R. Etheridge, Junr., Geol. and Pal, Q’land., 
1892, p. 230, t. 9, f. U), -W.S.D.] 
