342 Thos. Davidson—Brachiopoda of Brittany and S. Devon. 
in the Gulf of California, and which is charac- 
terized by one short median septum in the ven- 
tral valve (Fig. 2, 0), and two diverging ones 
in the dorsal one (Fig. 3, p). M. de Tromelin 
says that he has seen similar septa in both valves 
of Lingula Lesueuri, and indications of them are 
visible on the internal cast, Fig. 4. It will, 
therefore, remain a question for further consi- 
deration, whether the Lower Silurian species 
might not be referable to Dall’s genus Glottidia ? 
I may also mention that Mr. Vicary has recently 
found in a Budleigh Salterton pebble a speci- 
men of Lingula Lesueuri, with its peduncle fos- 
silized, Fig. 5. This is a remarkable occurrence, 
although not unique. 
Lingula Lesueuri is tolerably abundant in the 
Armorican Sandstone at Pontréan, Guichen, and 
Sion in Brittany. M. Moriere has found it in 
BL in uleeseeuht, beds of a similar age at Bagnoles—and M. de 
with peduncle, Bud- Tromelin has recently discovered it at Lairoles, 
leigh Salterton. near Roquebrun (Herault). 
3. Lincura ? Hawke, Rouault. Pl. X. Figs. 8—11. 
Lingula Rouaulti, Salter and Davidson. 
This remarkable species differs much from the common shapes of 
Lingula, although, as far as I could ascertain, it possesses similar 
muscular impressions, as will be seen by a glance at Figs. 9, 10, 11, 
of our Plate. J am, however, uncertain if it should not be removed 
from Lingula proper; but this must remain a question for future 
discussion. It is remarkably pear-shaped, and tapers a good deal at 
the beak. There appears also to exist on the internal cast of the 
ventral valve a narrow flattened margin, as well as a narrow median 
longitudinal depression, while the lateral portions of the casts are 
longitudinally striated (see Pl. X. Figs. 9,10). In external shape 
and character L. Hawkei is well distinguished from L. Lesueuri, L. 
Salteri, as well as from Dinobolus Brimonti. The exterior surface 
of the valves are marked with numerous close and fine concentric 
lines (Pl. X. Fig. 8). It appears abundant at Pontréan (Ille-et- 
Vilaine). 
4. Lincuna? Saurmri, Day. Pl. X. Figs. 12, 13. 
Lingula Salteri, Day. Sil. Mon. p. 53, pl. i. figs. 27-29, 1866. 
When I described and illustrated this remarkable species in 1866, 
my material was so scanty and incomplete that I felt somewhat un- 
certain with respect to its characters, or the genus to which it belonged. 
Since then M. Lebesconte has found several good examples of the 
shell at Pontréan, in Brittany. One perfect bivalve specimen, PI. 
XxX. Figs. 12, 12a, is almost circular, 21 lines in length and breadth by 
11 in depth, and shows that its valves are moderately convex, and. 
of about equal depth, the dorsal one most convex at the umbo, with 
slight mesial longitudinal depressions commencing at about half the 
