112 F. R. Cowper Reed—Girvan Crustacea, ete. 
recalling the caudal style of Ceratiocaris. The four segments and’ 
the style seem to belong to one and’ the same individual, and are- 
curved round into a rough circle so that the style overlaps and 
crosses the first of the segments. Thestyle has been slightly dis- 
placed, but seems to articulate with the last segment, though it is 
placed at what Messrs. Young considered the anterior end of the plate. 
It has the usual elongate slender triangular shape of a caudal style of 
Ceratiocaris, and tapers gradually to a point, though the latter is’ 
hidden by matrix. In length it is at least three times that of the 
last segment; it is slightly curved at the base, which is rounded, 
truncate, and slightly swollen, and the surface is longitudinally striated 
and very minutely g granulated, the granules being arranged in transverse’ 
linear series, giving the appearance of fine transverse striation. 
Young mentions a similar fine granular ornamentation on the plate 
of the type-specimen of Sol. solenoides. 
There are also in Mrs. Gray’s collection two elongated segments of’ 
probably the same species, but from Dow Hill and Ardmillan 
respectively ; they are much longer and narrower in proportion than 
the Balclatchie segments, one measuring 10°25 mm. long by 2 mm. 
wide at the anterior end, and the other 9mm. by 1:75mm.; they, 
decrease slightly in width posteriorly, otherwise they agree in characters: 
and ornamentation with the typical examples from Balclatchie. 
In the face of this new evidence it may be well to hesitate to refer: 
this fossil to the genus Helminthochiton ; and with the suspicion that 
it may ultimately have to find its place amongst the Phyllocarida we 
may return to the old generic name Solenocaris® without committing 
ourselves to any final decision on its affinities. 
The main points of distinction between the Balclatchie form 
S. solenoides, and the one from the Upper Bala beds of Penwhapple. 
Glen and Thraive Glen known as Helminthochiton Grayie have been 
pointed out by Professor R. Jones and Dr. Woodward, and need not 
be here repeated. But it may be added that in Sol. solenozdes the longi- 
tudinal ridges below the diagonal ridge are parallel and straight, and 
meet the diagonal at a very acute angle, whereas in H. Grayie they 
curve up to meet the diagonal at nearly a right angle. The plates of 
the former also are covered with a shining black chitinous substance, 
as is the case with Crustacea from the same bed, whereas this covering. 
is absent from the plates of H. Grayie, and they seem to be composed 
of a calcareous material, and are altogether thicker and stouter in 
substance. 
Dimensions of figured specimen showing four segments and style :—. 
Length of segments ae ane He .. 7°0-5°5mm., 
Height of ditto... sid as dae ..  03°0-2°5mm. 
Length of style... ae io .. +14°5mm. 
Estimated total length of ditto... a Us 18:0mm. 
Width of spine at base... He sat 2-0 mm. 
CrratiocaRis :(SoLENOCARIS?) sp. (Pl. IM, Figs.) YOs se) 
There are several specimens from Balclatchie in the Sedgwick 
Museum similar to the style-like body AUDIT a pearson of 
1 Nicholson & Etheridge: Mon. Silur. Foss. Girvan, fre, f i (1878), p- 207. se 
