190 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 antennae 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. 



