106 
HISTORY OR BRITISH CRUSTACEA. 
and its teguments horny. The outer antennse are furnished 
at the base with a very large plate, which conceals their 
origin. The legs are for the most part slender and very 
long, and the false swimming-feet are enveloped at the 
base by the lamellar prolongation of the segments of the 
abdomen. The tail-fin is large and well formed. This 
group is very extensive in species, and includes the well- 
known Shrimp and Prawn. 
Fam. CRANGONIDJV, M. Mw. 
Inner antennm inserted on the same line as the outer. 
First pair of legs terminate in a subcheliform hand. (Plate 
VIII. fig. 2 a , shows inner antennm ; fig. b , the outer.) 
The Arctic species of this family are much larger than 
the others. In some of the northern seas, particularly in 
the Bays of Spitsbergen, these Shrimps appear to abound, 
and must supply food even to the walrus and seal. 
Gen. 38. CRANGON, Fair. 
Carapace considerably depressed. First pair of legs 
strong, ending in a flattened hand, on the front edge of 
which there folds down a movable fang ; two next pairs of 
legs very slender— the second generally ending in two small 
