CRUSTACEA AND ARACHNIDA OF THE CARBONIFEROUS ROCKS. 517 
Glyptoscorpius perornatus, nov. sp., Pl. X XIX. fig. 16. 
The specimen from which the following description is taken, was found by 
WALTER Park, Esq., at Langholm, in the highly fossiliferous bed near that 
place. Like many of his other treasures obtained from the same source, it has 
been generously lent to the Survey for description. It exhibits the dorsal view 
of the posterior part of the left side of the carapace, and a little more than the 
left halves of five of the body segments still in place. In addition, the interior 
of a large portion of the sternal organs of the left side have been exposed by 
the removal of the anterior portion of the carapace, as well as several joints of 
one of the limbs, and the second joint of another. A narrow stripe along the 
broken margin gives an insight into the nature of the ventral plates correspond- 
ing to the dorsal ones preserved. The animal seems to have been truncated 
at the fifth body ring, the soft parts decomposed out, and the hollow partially 
filled in with mud before being entirely embedded. The greatest length 
of the specimen is 9 cm. (about 34 inches), and the breadth 8 cm. (83 inches). 
The carapace measures from the mid line to the posterior lateral angle 6 cm., 
the breadth of the carapace then must have been about 43 inches. From this 
the body tapers backwards to 8 cm. or 31 inches at the posterior margin 
of the fifth body segment. 
Carapace.—The portion preserved represents part of the hinder end of the 
head shield extending from the left margin to a little beyond the middle line. 
It measures from 6 to 7 cm. in breadth, by 2 cm. in depth. The portion 
which would bear the central eyes is therefore not preserved. At the left side 
the carapace is doubled under, so that a flange with the ornamented side 
turned downwards 5 mm. wide, is seen to extend for some distance beyond 
the portion of the carapace preserved. If the direction of this indicates the 
shape of the carapace, it should be nearly semicircular, with a radius of about 
6cm. The whole of this part is covered more or less with the characteristic 
scale-like ornamentation, while the posterior margin is graced with a deep 
fringe of scollops which have sub-parallel sides and rounded tips, each scollop 
having a bulging centre and a delicate raised edge, and being separated by 
grooves like knife cuts from its neighbours. The fringe is deepest near the 
mid line of the back, and dwindles-to less than half that depth towards the 
sides. Near the lateral edge a different ornament, like the long feathers on a 
bird’s wing, sets in, while on the flange the markings are V-shaped and pointed. 
Where the test is thickened, especially where two plates overlap, the ornament 
is considerably marred by the test being blown up with pyritous concretions, 
which have formed within its thickness. Many of these have decomposed out, 
leaving lines of honey-combed test, as shown in fig. 16. 
Cephalic Appendages.—The interior of four triangular plates, with interven- 
