ON THE FOSSIL PHYLLOPODA OF THE PALAOZOIC ROCKS. 223 
In the Museum of Practical Geology, London, there is a small specimen 
(D3), p- 11 of the ‘ Catal. Cambr. Sil. Foss” 1878), labelled ‘ Hntomidella, 
Lingula-flags, St. David’s,’ but it has no cross furrow, and resembles 
Caryocaris in outline. It measures +4, x 7} inch, and, though small, may 
be O. Wrightii. 
We have already remarked (see above, p. 7) that Mr, Salter recognised 
a Caryocaris among the Australian fossils exhibited at the International 
Exhibition at London in 1862. 
Lincuocaris, Salter, 1866. 
This was determined and described as a paleeozoic bivalved Phyllopod, 
from the Upper-Tremadoc schists of Tuhwnt-y-bwlch, Garth, Portmadoe, 
North Wales, by Mr. J. W. Salter, in the ‘Memoirs of the Geological 
Survey,’ vol. iii. (1866), pp. 252, 253, and 294. His description of the 
generic characters is as follows :—‘ A thin bivalve crustacean shell, with 
a generic form like that of a Modiola or Mytilus, with scarcely prominent 
beaks, and no? hinge-teeth; the surface of the carapace is covered by 
fine raised concentric lines.’ A description of DL. lingulecomes, Salter, 
follows, and this form is figured in pl. 10, figs. land 2. See also the 
‘Catal. of Cambrian and Silurian Fossils in the Geol. Mus., Cambridge,’ 
1873, p. 16, with a figure. 
In the Woodwardian Museum at Cambridge are two specimens of a 
bivalve (‘A 273’), there labelled ‘ Mytilocaris linqulecomes, Salter,’ from 
the above-mentioned locality, one of which, seemingly representing the 
outside, but somewhat crumpled longitudinally, approximates in its 
outline and size (1,3, x } inch = 32 x 12 mm.) to Mr. Salter’s restora- 
tion (?), fig. 1, pl. 10, and fig. in ‘Cat. Cambridge Foss.’ p. 16. The 
- other is a less perfect internal cast. Otherwise we have not met with 
any corresponding specimen. 
In the British Museum are casts of the insides of two bivalves 
(£48654’ and another), labelled ‘ Lingulocaris’; but, though probably 
belonging to Mr. Salter’s genus here mentioned, they differ much from 
its first species in ontline. They are longer, sharper at one end, and 
more nearly resembling a pea-pod in shape. This species may be dis- 
tinguished as DL. siliquiformis. One specimen (presented by the Rev. 1% 
J. F. Blake) is from the Upper-Tremadoe schists at Garth Hill, Port- 
madoc, and the other (‘48654’) is from the Bale schist at Bwlch-y- 
Gaseg, near Cynwyd, Corwen, collected by ‘J. R.’ 
In Mr. Salter’s figures of L. lingulecomes the furrow (slight as it is), 
passing obliquely from the umbo backwards to the upper part of the 
posterior margin is a very interesting feature, being emphasised and 
duplicated in the oblong and angular Myocaris, Salter, from the paleozoic 
pebbles of the Triassic conglomerate at Budleigh-Salterton in Devon. It 
is also represented in the oblong Solenocaris, J. Young, from the Llandeilo 
or Caradoc-Bala strata of Penwhapple in Ayrshire, but at a different 
angle, lower down on the surface, and accompanied with two other 
shallow furrows radiating from the umbo. These features are not without 
homologies in another Phyllopod, the Carboniferous Leaia, where radiating 
ridges, equivalent to the convex boundaries of the furrows in the preceding 
forms, are characteristic of the carapace-valves. 
