NCENIA. 
471 
A MP HIP OB A. P OB 0 CER IDES, 
NAT ATORI A. 
Genus— NCENIA. 
Noenia. Spence Bate, Cat. Amph. p. 271. 
Generic character. Antennae subequal ; superior pair with- 
out a secondary appendage ; inferior having the flagellum 
multi-articulate. Gnathopoda subchelate. Posterior pair of 
pleopoda biramous. Telson cylindrical. 
The animals of this genus are somewhat compressed. 
The eyes are round. The superior antennae are about 
the same length as the inferior ; the latter originate 
posteriorly to the superior, and terminate in a multi- 
articulate flagellum. The first two pairs of legs have 
subchelate hands, the second pair being much larger 
than the first. The walking legs are tolerably robust, 
and not very long. The posterior pair of caudal ap- 
pendages terminate in a pair of styliform branches. The 
middle tail-piece is tubular, and tipped with one or two 
rudimentary denticles. 
This genus bears considerable resemblance to Eurys- 
tlieus, and it is with much hesitation that we have 
placed them in different families.* The species are rare, 
and it is not improbable, when more individuals are 
obtained, that some of the supposed species here de- 
scribed, chiefly founded on the structure of the hands, 
may prove only varieties of other species. 
# We have not been able to identify the Gammarus spinipes of Dr. 
Johnson (Zool. Journ. iv. p. 417), taken among Sertularia, from deep water 
on the Berwickshire coast, but are inclined to refer it either to the present 
genus or to Eurystheus, the character given of the first two pairs of legs 
agreeing tolerably well with those of Eurystheus bispinimanus (ante, p. 357). 
