88 SEA-SHORE LIFE 
feeding they could be rendered more palatable for market than 
when subsisting upon their natural diet. At present the fishery is 
worth not more than $2500 per annum. 
An admirable description of the anatomy of the crayfish is 
given by T. H. Huxley in “A Manual of the Anatomy of Inverte- 
brated Animals,” 1891, p. 264; 
and also in the International 
Scientific Series, “The Cray- 
fish,” 1880. 
In the neighborhood of 
New York we find three com- 
mon species. In Cambarus 
bartonit, Fig. 55, the body is 
devoid of spines, but is pitted 
with little depressions scat- 
tered at fairly regular inter- 
vals. It is very abundant in 
running streams, and often 

hides away under stones or 
burrows into gravel. Large 
Fig. 55; BROOK CRAYFISH. Orange specimens may be three inches 
Mountains, New Jersey. in length. 
Tn Cambarus blandingii the 
body and claws are besprinkled with tubercles. It is dull greenish- 
brown, whitish beneath and lives in clear, running streams; often 
resting near the surface upon water plants, with its head pointed 
up stream. It grows to be over five inches in length. 
Cambarus affinis is the crayfish which is commonly sold in the 
New York markets. It grows to be a little over four inches long, 
and the upper surface is mottled with darker and lighter shades of 
green, while the tips of the nippers are orange. The under sur- 
face is streaked with chestnut-brown It is common in the rocky 
beds of rivers, and often rests under flat stones, but avoids dense 
clusters of water plants. 
SHRIMPS AND PRAWNS 
These are generally smaller than the lobsters and crayfishes. 
Moreover, they are swimming creatures while lobsters and cray- 
