190 E. A. Anprews, Spermatophores in Panulirus and Paribacus. 
hairs may be of importance in determining the temporary positions 
of the various parts of the body. 
If setae at the joints have any such function the setae we 
assume to phylogenetically preceed the thumb and finger of the above 
described cleansing elaws and which might be homologized with 
these “Stellungshaare” may also have been concerned with special 
stimuli that determined the positions of the limb. 
The opposing pair of receptors, the setae on each side of the 
last joint of the leg, might then continue to act in controlling the 
amount of bending at this joint while elevations, finger and thumb, 
were formed and perfected by some unknown means in the course 
of generations and finally the perfected claw would be essentially a 
receptor for mechanical stimulation, though secondarily a cleansing 
organ for use in other parts of the body. 
All that would be thus explained would be the occurence of 
special setae on the claw and their representation on even the 
rudimentary claw of the male. 
Johns Hopkins University, October 1911. 
Bibliography. 
1. ANDREWS, E. A., Sperm transfer in certain decapods, in: Proc. U.S. 
nation. Mus., Vol. 39, 1911. 
2. —-, Breeding habits of Crayfish, in: Am. Nat., Vol. 38, 1904. 
3. GIESBRECHT, W., Stomatopoden, in: Fauna Flora Golf von Neapel, 
Vol. 33, 1910. 
4. DorLEINn, F., Lebensgewohnheiten und Anpassung bei dekapoder 
Krebsen, in: R. HERTwIG's Festschr., Vol. 3, Jena 1910. 
