220 REPORT—1883. 
seven of the anterior ones; appendages not known; }.297. Caen[Caer]- 
y-coed, near Maentwrog [Lower Lingula-flags]. Mr. D. Homfray. 0. 
297, body-segments of the same. Same locality and donor.’ The figure 
appended in the outside column is H. vermicauda, given as a generic type. 
In the Woodwardian Museum at Cambridge are three specimens, 
A /160 (two), and A/174, from the uppermost part of the Lower Lingula- 
flags at Caer-y-coed quarry, and labelled as belonging to H. ? major, 
Salter. 
1. One of them (<a) is a large oblong valve measuring 4,°, by 2 inches, 
truncate (with slight convexity of outline) at one end, and obliquely rounded 
at the other; the greatest convexity of the broad (posterior P) end being 
a very little above the median line of the valve, and that of the narrower 
end considerably above that line. This appears to be a right valve, gently 
hollow, showing its inside; it is a mere film on the black schist, and is 
delicately plaited and gently undulate throughout, in lines parallel to the 
long axis of the valve, cleavage-pressure having compressed and corrugated 
the surface from edge to edge; and at the posterior (?) end of the valve 
the margin is barely perceptible, being fringed off by its extremely plaited 
state, or (in other words) frittered away in longitudinal shreds parallel 
with the plaiting of the schist, showing, probably, that this end was of 
thinner consistence than the rounded end. This condition often occurs 
with the ends of phyllopodous specimens in the Lingula-flags. There are 
also some irregular concentric lines in the antero-ventral area, caused by 
the depression of the convexity of the valve. By lateral pressure the 
specimen must have lost something in height, and has had its length 
exaggerated. This specimen is evidently the one referred to in the ‘ Rep. 
Proc. Geol. Polytech. Soc. W.Y.’ iv. p. 589, which was at first thought 
to be a ‘ hollow oblong scute, after the manner of Apus;’ but the ‘ three 
distinct ridges on the hinder border’ are not at all visible. Though of. 
extraordinary size, this may be regarded as a Hymenocaris, after Salter’s 
determination, in the absence of evidence to the contrary. The occurrence 
of single valves is not uncommon, though the carapace does not appear to 
have been sutured, 
2. The second specimen in the Woodwardian Museum, also marked a F 
is of smaller size (3; x 7 inch), narrower, and more silicular in 
shape; and it has a distinctly emarginate posterior end, though this 
feature can be recognised in the black schist only by reflected light at a 
certain angle. It is coarsely plaited lengthwise, narrowed (contracted in 
height), and much lengthened. The emarginate or sinuous end is different 
from that of Hymenocaris, and similar to that of Ceratiocaris. Nevertheless, 
it may possibly (though not probably) have been produced by the strong 
tendency of the schist to take on a state of cleavage, crumpling up the 
posterior margin by pressure contrary to its direction. 
On the other hand, a smaller specimen (marked =) from Wern, near 
Portmadoc, in somewhat similar schist, but not ‘ plaited,’ shows a definitely 
emarginate, sinuous, or ogee posterior margin, and thus presents a marked 
feature of Ceratiocaris. This is a posterior moiety of a valve, 5°; long x 45 
inch high, As the abdominal part of Ceratiocaris ? latus, Salter, and the 
telson-spines of C. ? insperatus, Salter (‘Mem. G. 8.’ ili. pp. 294, 295) 
come from the Upper-Tremadoc schists, near Portmadoc, we may regard 
