ORDER PHYLLOPODA — APUS. 61 
ORDER VII. PHYLLOPODA. 
Shield delicate, of a single piece, free behind. Two corneous mandibles, semicylindrical, 
without palpi ; the tip comp?essed, straight and dentate. First pair of feet oar-shaped, 
and terminating in articulated sete ; the others branchial, and composed of more than 
sixty pairs. 
(EXTRA-LIMITAL.) 
Genus Apus, Scopoli. Head confounded with the shield, which is soft, subcrustaceous, rounded, oval, 
emarginate behind. Tail short, jomted, ending in two long threads. Antenne two, short, 
simple. Three sessile, unequal eyes. 
A. caudatus, (Binoculus id. Say, 1. c. Vol. 1, p. 437.) Body subovate. Antenne more than half 
as long as the body. Tail of three segments, half as long as the body; second segment transversely 
quadrate, narrower than the first in the female, elongated and attenuated in the male. Length, 
0°01. Florida. 
Oss. I place this species here with some hesitation. It is probable also that near this will be 
placed that singular crustaceous fossil described in the Annals of the Lyceum of Natural History 
of New-York, Vol. 1, p. 375, pl. 29, under the name of Eurypterus remipes. Milne-Edwards 
appears disposed to think that it forms a passage between the Isopoda and Branchiopoda, 
