392 CEUSTACEA 



C. limosus (Rafinesque) (C. affinis Say) (Fig. 624, B). First pair of 

 abdominal appendages of the male terminated with 2 short, straight, diver- 

 gent tips; length 10 cm.; body hairy all over; sides of carapace spiny; 

 rostrum broad with parallel sides: eastern North America, not west 

 of the Alleghenies; common in the larger rivers, usually does not 

 burrow; the crayfish which is most commonly sent to the New York 

 markets. 



C. pellucidus (Tellkampf) (Fig. 625). First pair of abdominal 

 appendages clavate, the outer part being truncate and toothed; eyes 

 atrophied; length 9 cm.: in caves in Indiana and Kentucky. 



C. diogenes Girard (Fig. 624, D). First pair of abdominal appen- 

 dages in male terminate with 2 strongly recurved tips; rostrum rather 

 slender ; length 8 cm. : widely distributed and often common in the entire 

 country east of the Rocky Mountains ; preeminently a burrowing species, 

 being found in swamps and meadows often far from a stream; the bur- 

 rows are from 1 to 3 feet deep, with an enlargement at the bottom filled 

 with water; often with a chimney to the height of several inches over 

 the top. 



C. virilis Hagen. First pair of abdominal appendages in male acute, 

 tapering, divergent; length 8 cm.: common in central states, in large 

 rivers and lakes. 



0. propinquus Girard (Fig. 624, A). First pair of abdominal appen- 

 dages in male terminating in 2 elongate straight convergent tips; length 

 7 cm. ; rostrum with a median ridge : common throughout the central part 

 of the country, especially in large rivers and lakes. 



FAMILY 3. PALINUEIDAE. 



Spiny lobsters. Body of large size; antennal scale absent; none of 

 the periopods chelate: several genera. 



PANTILIEUS Gray. Rostrum absent ; flagella of antennae long : several 

 species. 



P. argus (Latreille). Florida crayfish. First pair of antennae with 

 a very long basal joint; body 20 to 40 cm. long; color violet, red, and 

 brown : common on coral reefs off the Florida coast ; an important article 

 of food. 



TRIBE 4. ANOMURA. 



Last pair of thoracic legs reduced in size and extend backwards and 

 upwards ; a swimming fin usually not developed : 2 families, both marine. 

 Key to the families of Anomura: 



Oi Animals burrow in the sand 1. HIPPIDAE 



o a Animals live in snail shells ; hermit crabs 2. PAGURIDAE 



