LOWER CARBONIFEROUS ROCKS OF ESKDALE AND LIDDESDALE. 85 
Abdominal Appendages—The appendages on the first abdominal segments 
seem to be modified for sexual purposes. Figs. 9b and 9c show articulated 
with this a stout longish limb-like appendage, made up of five joints, which 
reminds one somewhat of the corresponding modified limb of the male cray fish, 
Astacus fluvialitis, only it is much larger in proportion. The best preserved case 
of this is shown magnified in fig. 94 Analogy would incline one to look at 
those other individuals exhibiting the above character as males. The ap- 
pendages on the next four segments appear as short and flattened, the seg- 
mentation not being traceable in the present state of preservation. The 
appendages of the sixth segment are made up of the broad propodites articulated 
with it at its posterior angles, each of which gives rise to a pair of swimming 
flaps with strengthened ridges ; those of the exopodite are blade-shaped and 
slightly curved outwards. The telson is long and hastate, and supports a couple 
of spines on each side. Test smooth, or only slightly pitted in appearance very 
like that of a shrimp. 
Observations.—It will be at once observed, from the enlarged lobes of the 
second abdominal segment and their overlapping each way, that it was here the 
animal doubled itself while swimming, just as in our recent shrimps. Like P. 
socialis, Salter, it often occurs in great numbers. It differs from that species 
in the shape of the carapace and in the pleure of the first and second 
abdominal segments as well as in the more elongated telson. 
Locality—River Esk, 4 miles south of Langholm, Dumfriesshire. 
Horizon.—Cement-stone group, Lower Carboniferous. 
Note.—Since the above was written, the Rev. THomas Brown, F.R.S.E., in 
whose possession the specimens of P. soczalis are from which Mr SALTER made 
the genus, has kindly allowed me to see them. There is no doubt that our P. 
Eskdalensis belongs to the same genus, but there is sufficient difference to 
warrant its being ranked as a separate species. 
Genus Palwocaris, Meek and Worthen, 1865, Proc. Acad. Nat. Sci., 
Philadelphia, 1865, p. 48. 
Paleocaris Scoticus, nov. spec. (Pl. X. figs. 10 to 10/4). Body long and 
narrow, and tapering backwards. Length from ofan inch tolinch. The cara- 
pace only extends over the cephalic segments, and measures about two-sevenths 
of the body irrespective of telson and appendages. It is rounded in front, 
and its posterior margin somewhat concave. It is divided into several areas by 
deep sulci. One of these of a V-shape extends slightly back from the anterior 
margin, and has its apex directed backwards. Other two proceed from the 
anterior portion of the lateral margins, and reach the posterior margin after 
having performed crescent-like curves, the convex sides of which are directed 
inwards ; from these latter short grooves inwards proceed, but do not meet on 
the median line. 
