ON THE FOSSIL PHYLLOPODA OF THE PALZOZOIC ROCKS. 425 
near to each other, often close together, more or less parallel, and generally 
with the same end in one direction. On the plate at page 2, some of 
the best preserved specimens have been selected and outlined just as the 
individuals lie on the stone; sometimes as figs. 1 and 2; 9, 10,11; and 
7, 15, 16, 17, in groups. 
These carapace-valves are more or less oval-oblong in outline, but 
often imperfect, and in nearly all cases modified in shape by lateral 
pressure. 
The largest individual (fig. 1), 40 mm. long and 22 mm. high (broad), 
having probably its original shape or nearly so, has its upper aud lower 
edges slightly convex and nearly parallel; the upper (dorsal) edge is 
somewhat more fully curved than the other, especially in the antero- 
dorsal region. The front end (to the left-hand in the figure) was pro- 
bably rounded, but is broken; the hinder extremity is obliquely truncate, 
but bears some indication of an ogee curvature, such as is seen in many 
Ceratiocaride and other Phyllocarids. Three abdominal segments (one 
imperfect) are still attached to this end of the carapace; the first two 
are about 5 mm. long and the third about 7mm. They appear to have 
been originally as deep as the carapace, and each segment at its hollow 
eurve below its convexity and lateral articulation was marked with 
vertical strie. 
The surface of fig. 1 bears five delicate, longitudinal, gently-curved, 
sub-parallel lines. These lines are partly raised and partly hollow, as if, 
having a consistency different from that of the rest of the valve, they 
have been differently affected by the pressure to which the matrix had 
been subjected. 
Fragments of probably a specimen similar to fig. 1 lie close to it, as, 
shown by fig. 2. 
There is a remarkable similarity in outline between fig. 1 here de- 
scribed and the fig. 1 at p. 179 (in our Sixth Report, 1888), ‘Report Brit. 
Assoc.,’ 1889, which we determined at pp. 175 and 176 of that Report to 
be the Saccocaris major of Saiter. Although the relative size differs very 
much (11050 mm. and 37x22 mm.), and the proportions are also 
somewhat different (110 x50 : 101 x66), we are inclined to refer the 
two specimens (both of which are from the Cambrian rocks) to the same 
genus. Probably, if it were not for the broken anterior border in the 
new form, and the broken posterior margin of Saccocaris major, they 
might have presented a still stronger likeness. 
We provisionally regard this form as a new species, and call it 
SaccocaRis minor, fig. 1, p. 427, and define it as follows :— 
Carapace valve sub-oblong, arched above, nearly straight below, 
elliptically rounded in front, with the acme of curvature probably coinci- 
dent with the mesial line of the valve; truncate behind, with a slightly 
projecting and blunt angle at its upper fourth. Surface marked with five 
longitudinal, slightly-curved, sub-parallel lines, somewhat like the nervures 
in an insect’s wing; one or more of the lines seem to branch backwards. 
Abdominal segments present (see fig. 2, p. 427), and are of considerable 
interest as connecting this old form with Hymenocaris (see figs.°3, 4, and 
5 at p. 179, ‘Report Brit. Assoc.,’ 1889), and with Ceratiocaris and other 
allies. Some of the caudal spines are obscurely preserved on the slab. 
Owing to the pressure that has so greatly affected the other speci- 
mens on the two counterpart faces of the split slab, there is considerable 
variation in the outlines of the individuals, nor do they quite match fig. 1. 
