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GAMMARID/E. 
far advanced as the central one. The body is smooth, and 
not compressed. The third segment of the tail is very long, 
and the three posterior segments are inflected and inclosed 
beneath it. The eyes are small and round, and the su- 
perior antennas are short, — about as long again as the 
head ; the secondary appendage is nearly as long as the 
flagellum. The inferior antennae are a little longer than 
the superior. The first two pairs of legs are small, 
slender, and feeble, scarcely subchelate, the fingers being 
almost rudimentary. All the others are more robust, 
and have the fingers wanting, being replaced by two or 
three stout spines. The second and third pairs have the 
wrists short, but as broad again as long, and the hands 
increase in breadth from the articulation to the distal 
extremity, somewhat in the shape of a pear. The hand 
is capable of being impinged against the wrist, thus 
forming an imperfect prehensile organ. The next three 
pairs have most of the joints broadly developed, and lie 
folded against the sides of the animal, somewhat resem- 
bling scale armour. The swimming legs are short, and 
the three caudal appendages are short and spinous. The 
terminal plate is single, but deeply divided, and each half 
is dilated so as to overlap the other. The animal is not 
very hairy, but the hairs it possesses are of very diversi- 
fied forms, some simple, others toothed in a variety of 
ways, both in single and double rows, while others are 
plumose and ciliated. 
This singular creature lives on the coast, on sandy 
shores, between the tide-marks, coming to the surface 
when the tide is in, and again burrowing beneath it when 
the ebbing waters leave the sand dry. We have observed 
that they generally make a furrow in the sand, about a 
foot long, at the extremity of which we took them about 
an inch beneath the surface. 
