ON THE FOSSIL PHYLLOPODA OF THE PALHOZOIC ROCKS. 219 
hinder margin seems to be well founded, whether the abdomen be still in 
apposition or not. 
The crumpled bed-planes of the schists frequently exhibit crushed 
body-joints of the Hymenocaris ; but these relics of the abdominal portion 
vary much in the number of attached segments. Sometimes four or five, 
but not uncommonly six or seven, body-joints occur, with or without the 
telson being apparent. Hight or nine together are less frequent. In one 
instance (in the Owens College Museum) eleven segments can be counted, 
besides an obscure telson, in an unattached body lying on a slab contain- 
ing numerous specimens of carapaces and body-rings of Hymenocaris 
(from Carrig-felen, collected and given by Mr. D. Homfray). In this 
case, some (five or six), which appear to have been narrower and softer 
than the others, may have been within the carapace, for they differ from 
the others in size and distinctness of outline. The crushing and squeeze 
haye rendered even the best and most promising specimens so obscure 
that much doubt still exists in the observations on this Phyllopod. Mr. 
Salter determined nine exposed body-rings (op. cit. p.293; but only eight 
shown in t. 2, f. 4), with one pair of styles and two pairs of stylets 
attached to the last joint (op. cit. t. 5, f. 2). The abdominal joints vary 
from about ;3, to 74; inch in height, sometimes to +5, very rarely to 
36; and ;7,;, but in one case to 48; inch, according to size of individuals 
and the accidental crush. 
Hymenocaris vermicauda occurs in the Lower Lingula-flags, espe- 
cially ‘in the upper portions of the true Lingula-flags’ (Salter, op. 
cit. p. 293, and ‘Catal. Pal. Foss. Cambridge Mus.’ p. 10), near Tre- 
madoc, Ffestiniog, Trawsfynydd, and Dolgelly. The particular localities ' 
are: the railway-cutting near Wern, not far from Penmorfa; Pentre- 
felen, west of Penmorfa; Careg-felen ;, Bryntwr Summerhouse; and 
especially the hill descending to Penmorfa Church; Moel-y-gest, the hill 
behind Portmadoc; Borth cove or harbour near Portmadoc; also at 
Ffestiniog ; Gwen-barent (Gwern-y-bareud, op. cit. p. 294), Moel-hafod- 
owen, and other places near Dolgelly; and doubtfully at Pont Seiont, 
Caernarvon. A specimen in the British Museum is from the ‘ Upper 
Tremadoc’ schist (or hard shale) of Garth, near Portmadoc. 
The rippled flagstones of the Lingula series near Tremadoc, at the 
village of Y-Felin-Newydd, and near Pentrefelen and Wern, on the 
Criccieth road, are marked with tracks referred, with good reason, by 
Mr. Salter to Hymenocaris vermicauda (‘ Quart. Journ. Geol. Soc.’ vol. x., 
sick pp- 208-211; and ‘Mem. Geol. Surv.’ vol. iii. p. 248 and p. 294,. 
pl. 1). ; 
The foregoing observations apply to H. vermicauda. Mr. Salter noticed 
another fossil from the Linguia-flags, which he referred to the same genus 
in 1873, having, however, designated it Sacocaris in 1867 (afterwards 
spelt Saccocaris correctly). 
In the ‘ Catal. Pal. Foss. Cambr.’ p. 7, Mr. Salter entered the species 
as ‘ Hymenocaris (Saccocaris, Halifax Trans.? 1867) major, Salter, n.s. 
A large ovate carapace, strongly emarginate behind, and larger than 
H. vermicauda (see p. 10). Body-segments broad and short, at least in 
' Mr. David Homfray, who collected the larger portion of the known specimens 
of this genus, has favoured us with a note of the localities. 
? This is a mistake for Report Proceed. Geolog. Polytech. Soc. W. Riding, Yorkshire, 
for 1867 (Leeds, 1868). The reference is vol. iv. p. 588, ‘On Sacocaris: a new genus 
- of Phyllopoda, from the Lingula-flags,’ by J. W. Salter, A.L.S., F.G.S. 
