Paleozoic Bivalved Entomostraca. oon 
In the confused mass of casts and crushed valves, adherent 
in fragments, which compose the hand-specimen before us, it 
is difficult to find even a tolerably perfect outline, and real 
features are not easily determined. Fig. 4, a, however (a 
nearly perfect valve, 4 inch long), shows a rather long hinge- 
line and oblong shape, like that of fig. 1, @, and of the large 
and oblong individuals of LZ. balthica (Ann. & Mag. Nat. 
Hist. 7c. pl. vi. figs. 1, 2,4, and 5). On the other hand, 
fig. 4,6, a smaller valve, ;'; inch long, seems to have an ovate 
outline, approaching that of Schmidt’s fig. 23, before alluded 
to. In this case small specimens of the two kinds (oblong 
and ovate) occur together; but still the latter is the smaller 
(younger?) of the two. These badly-preserved specimens 
may be dwarfs of L. balthica. 
2. Leperditia balthica (His.), var. contracta, nov. 
(Pl. XIX. figs. 2, 3, 13, 14, and 17.) 
Pl. XIX. figs. 2 a, 2 6. This small specimen is from the 
same place and collection as fig. 1, and is marked “No. 
58893” in the British Museum. It is 3% inch in length, and 
is a broadly-ovate right valve, with a decidedly long dorsal 
edge; but it is well rounded ventrally, and convex at the 
centre. It altogether wants the oblique ellipticity of Schmidt’s 
fig. 22 (var. of his LZ. Hisingert) to be the same as that, and 
its hinge-line is too long; but at the same time it is too short 
and too much rounded ventrally for a true L. balthica. 
This specimen approaches some forms of L. canadensis, 
such as fig. 11, a, pl. ix. Ann. & Mag. Nat. Hist. ser. 3, vol. i. ; 
but it is larger and its convexity is central. Taking all its 
features into consideration, I must regard it as a small variety 
of L. balthica, to be distinguished under the name of var. 
contracta. 
Casts of small Leperditie, from about 7%; to 7% inch long, 
similar in shape to fig. 2a, occur in the brown sandstone of 
the Kington Tilestones, Herefordshire (from Mr. R. W. Banks), 
and in the green shale of the Passage-beds near Ludlow (from 
Prof. John Morris), and with Beyrichia Wilckensiana in an 
olive-brown micaceous shale of the same series. 
Pl. XIX. fig. 3. Thisis a brownish internal cast, in greenish 
fine-grained micaceous mudstone, of a small right valve, 
about 7%; inch long, somewhat crushed, from the Lower Lud- 
low beds at Leintwardine, near Ludlow*. It was collected by 
* Mr. G. Cocking, of Ludlow, has found a similar specimen in the same 
beds at Church Hill, Leintwardine. In the ‘Catalogue of the Fossils 
in the Museum of Practical Geology,’ 1865, p.38, a Leperditia is quoted 
as ‘balthica” from the Wenlock Limestone of Ferriter’s Cove, Dingle, 
Treland; but I have not yet examined the specimen. 
