﻿SACCOCARIS MINOR. 



87 



curved than the other, especially in the antero-dorsal region. The front end 

 (to the left hand in the figure) was probably rounded, but is broken ; the 

 hinder extremity is obliquely truncate, but bears some indication of an ogee 

 curvature, such as is seen in many Ceratiocaridse and other Pbyllocarids. 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 7 mm. They appear to 

 have been originally as deep as the carapace, 1 and each segment at its hollow 

 curve below its convexity and lateral articulation was marked with vertical strige. 



The surface of fig. 8 bears five delicate, longitudinal, gently curved subparallel 

 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 the foregoing lay close to it, as 

 shown by fig. 2, p. 425 of the Report for 1890 (Eighth Report). 



There is a remarkable similarity in outline between PI. XIV, fig. 8, here 

 described, and fig. 6, namely, Saccocaris major, Salter. Although the relative size 

 differs very much (110x50 mm. and 37X22 mm.), and the proportions are also 

 somewhat different (110 X 50 : 101 X 66), 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 fig. 8, and the broken posterior 

 margin of Saccocaris major, they might have presented a still stronger likeness. 



We have regarded this form as a new species, and named it Saccocaris minor, 

 defined as follows : 



Carapace valve suboblong, arched above, nearly straight below, elliptically 

 rounded in front, with the acme of curvature probably coincident 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, subparallel lines, somewhat like the nervures in an insect's wing ; one 

 or more of the lines seem to branch backwards. Abdominal segments present 

 (see PI. XIV, figs. 8 and 9, and other figs, in Report for 1890), and are of 

 considerable interest as connecting this old form with Hymenocaris, Ceratiocaris, 

 and other allies. Some of the caudal spines are obscurely preserved on tbe slab. 



Owing to the pressure that has so greatly affected the specimens 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. 8, PI. XIV. Fig. 3 

 (Report of 1890) measures 27x15 mm. ; fig. 4 (1890), 27 X 10 mm. ; fig. 7 (1890), 

 28X11 mm. ; fig. 9 (1890), 23 X 7 mm. ; fig. 11 (1890), 25 X 8 mm. Nevertheless 

 some features of fig. 8, PI. XIV, are traceable in the majority. Looking at the 



1 This would agree with Mr. Salter's suggestion that the body-rings in S. -major were probably 

 as high (wide) as the valve itself. 



