260 MARINE INVERTEBRATES 
Prawns are known as crevettes in France and as Garnelen in 
Germany, where they are largely used as food. In the United 
States the shrimp-fishery is an industry of the South. On the 
California coast the fisheries are very extensive and are monopo- 
lized by the Chinese. 
Genus Penceus 
P. setiferus. This species is about six inches in length when full- 
grown. A ridge or crest extends along the center of the carapace, and 
terminates in a long, pointed, toothed rostrum, the teeth being fringed 
with hair on the inner side. The antenne are a foot or more in length; 
there are chelz on the first three pairs of thoracic feet; the swimming- 
feet and lateral margins of the segments of the abdomen are fringed 
with hair; and the caudal appendages are longer than the telson. It 
ranges from Virginia southward, and is very abundant on the shores of 
the Southern States, where it is gathered for the markets. The large 
ones are known as prawns and the small ones as shrimps. 
P. brasiliensis. This species is associated with P. setiferus, and, al- 
though not so abundant, forms a part of the shrimp-supply in the fisher- 
ies. It differs from the former in having a groove on each side of the 
ridge which runs through the center and whole length of the carapace. 
The first three pairs of feet are chelated. This shrimp is found as far 
north as Long Island, and often in brackish water, or even where the 
water is quite fresh. 
Genus Palemonetes 
P. vulgaris (Pale- 
mon vulgaris). Aver- 
age size one half of an 
inch in length; body 
translucent, almost color- 
less, irregularly spotted ; 
rostrum as long as cara- 
pace and toothed on the 
upper edge. It is found 
: among eel-grassin brack- 
ish water, and also in pools and ditches on muddy shores from 
Massachusetts Bay to Florida. Commonly known as prawns. 
Palemonetes vulgaris ; male. 
GEenus Crangon 
C. vulgaris, the common sand-shrimp. It ranges from Labrador to 
North Carolina on the Atlantic coast and from Alaska to southern Cali- 
fornia on the Pacific coast. It is found in abundance on sandy shores at 
low-water mark, and in shallow water below tide-mark; also among 
rocks and seaweeds. When left by the tide it buries itself in the sand. 
Its color varies with its location, rendering it inconspicuous. Upon the 
