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1. The crust covering cephalo-thorax on back and sides. 2. Under surface 
of head between the lower antennae. 3. Furnished with nippers. 4. Projec- 
tion from front of head, between antennae. 5. In the male crawfish the first ab- 
dominal legs are stiff and unlike theothers: in the female similar to the others, 
but rudimentary. 6. Space on back of thorax between the two longitudinal 
curved lines. 7. Ridged longitudinally. 8. The many-jointed terminal 
part of antennae 9 Front pair of jaws, 10. Jointed feelers. 11. Joint 
preceding hand. 12. Hind pairs of jaws. 13. The thick, longer-jointed 
basal part of antennae. 14. A very short flagellum attached beside the 
principal one. 15. Side-plates concealing attachment of legs. 16. Last 
joint claw-like, shutting against the enlarged preceding joint like the blade 
of a pocket-knife against its handle. 17. Rudimentary last segment of the 
body. 18. Under surface of the body between bases of the thoracic legs. 
19. Undivided basal joint of leg. 20. Pair of appendage 5 at tip of ab- 
domen. 21. The strong, jaw-like organs in front of head. 22. The forked 
tip of the abdomen. 
APPENDIX. 
Descriptions of- the following extra-limital species are added for the 
purpose of calling the attention of collectors to them, as it is very likely 
that they will be found in the state. The descriptions of crawfishes are fur- 
nished by Mr. Bundy, who has made a careful study of the species of 
Cambarus found in this and adjoining states. 
C. sloanv , Bundy. Rostrum quadrangular, subdeflexed, slightly concave, 
toothed in front, acumen long, acute, straight, cephalo-thorax, finely punctate 
above, granulate on sides, front margin angulated, lateral tooth long, acute ; 
epistoma wider than long, narrower in front, concave below, apex einargi- 
nate ; third maxillipedes smooth below, hairy within, hands short, thick, 
wide, smooth, fingers short, straight, not gaping at base, generally tipped 
with black, arm and wrist nearly smooth, at most with a few blunt teeth ; 
third legs with third joints hooked : first abdominal legs short, bifid, outer 
part slightly lcmger, flattened, bent outward at apex, slightly recurved, 
acute, tubercles at inner base small, inter-pedal space once and one-half 
longer than wide. The female has ventral ring rhomboid, posterior angle 
swollen, irregularly tuberculate, fissure transverse, anterior angle depressed. 
Habitat : Southern Indiana, Kentucky (Dr. Sloan). 
C. debilis , Bundy. Rostrum wide, quadrangular, subdepressed, concave 
above, foveola at base, margins nearly parallel, anterior teeth prominent, 
acumen acute, flat, smooth, cephalo-thorax subdepressed, punctate above, 
granulate on sides, lateral tooth acute, dorsal area narrow, wider behind, 
