Paleozoic Bivalved Entomostraca. 345 
Fig. 8 is a perfect carapace, in outline, of L. fabulites, 
var. josephiana, with a length of 35 inch and a height of 
zy Inch, from Lebanon, Tennessee, U.S., and was also given 
to me by Prof. J. Hall. 
Pl. XX. figs. 4 and 5. The specimens here figured were 
selected from among many crushed individuals forming a 
piece of Leperditia-rock, labelled “ Neile Bay,” and commu- 
nicated by E. B. Tawney, Esq., F.G.S., as a fragment of a 
larger mass in the Museum of University College, Bristol. 
If “ Neile Bay” be the same as, or near to, Port Neill, in 
Prince-Regent’s Inlet, in extreme North America, the occur- 
rence there of such Leperditice as these, which have a Lower- 
Silurian aspect (being apparently identical with LZ. canadensis 
and L. fabulites), would not. be strange. 
Fig. 4 is the outline of a left valve, broken along the ven- 
tral margin, and about + inch long. What remains of the 
valve indicates the proportions of L. fabulites (josephiana). 
Fig. 5 is a left valve, apparently retaining its outline, but 
broken at the centre, where it shows another similar valve 
underneath, symmetrically squeezed within it. This speci- 
men is about 7 inch long, and has the subquadrate outline, 
long hinge, and sharp dorsal angles of the typical LZ. cana- 
densis. 
8. Leperditia Billingsti, sp. nov. (Pl. XX. fig. 9.) 
This is the internal cast, in white limestone, of a subcylin- 
drical carapace, and is not quite perfect at the dorsal corners 
or ends of the hinge-line. It is from the Lower-Silurian 
(Trenton ?) strata, near (to the west of) Lake Winnipeg and 
north of Lake Superior. In length it is 3, and in height 
yy inch. This unique specimen was sent to me by the late 
W. Billings, Esq., then paleontologist to the Geological 
Survey of Canada, in December 1858. In its cylindroid 
shape and in its relative length, height, and thickness this 
Leperditia differs from all the North-American species, and has 
too true a parallelism of the upper and lower margins to be 
compared with any allies of L. phaseolus. Nor has it any 
analogue except the less convex Upper-Silurian LZ. parallela of 
Schmidt’s Russ. silur. Lep. 1873, p. 18, figs. 24-26, and the 
minute L. parallela, J. & K., of the Carboniferous rocks of 
Bavaria (Ann. & Mag. Nat. Hist. 1865, ser. 3, vol. xv. p. 407, 
pl. xx. fig.6). I name it after its discoverer. 
9. Leperditia alta (Conrad). 
Among the Upper-Silurian Leperditie of North America 
