330 A HISTORY OF RECENT CRUSTACEA 
CHAPTER XXII 
TRIBE It —-FLABELLIFERA 
THE name refers to the circumstance that in all the 
members of this tribe the terminal segment in conjunction 
with the uropods forms a caudal fan as in the Macrura, 
although here the telson is often not articulated, but fused 
with the preceding segment. The heart is situated chiefly 
in the pleon, only penetrating one or two of the terminal 
segments of the pereon. Respiration is effected by the 
help of pleopods acting as branchie. 
The families included are the Anthuride, Gnathiide, 
Cymothoide, Serolide, Spheromide, and Limnoriide. 
The term Cymothoide is used comprehensively for a 
closely connected group of families, as will be explained 
hereafter. 
Family 1.—Anthuride. 
The body is long and narrow, subcylindrical or 
depressed. The head is usually shorter than the following 
segment. The pereeon has its seven segments distinct. 
The first five segments of the pleon may be all distinct or 
completely or partially coalesced; the sixth is sometimes 
fused with the linguiform telson. ‘The mouth-organs are 
suctorial. The first gnathopods are usually the larger, 
subchelate; the second gnathopods and first pereeopods re- 
sembling them in general form. The other peraeopods are 
ambulatory. There appear to be no separate marsupial 
plates. The first pleopods are large, commonly expanded 
to cover the rest. The uropods have a two-jointed inner 
branch, and the one-jointed outer branch usually so arti- 
culated as to arch more or less over the back of the telson. 
