510 K. T. LEWIS, NOTE ON SOLPUGA FEROX. 



from the stem, ami in addition to these there are numerous 

 filaments which pass down the stem in a bundle and spread 

 throughout the fan in a dense plexus. The convex lower edge 

 of each fan is bordered with fine vertical striae about the 

 1/10, 000th of an inch apart, and immediately above these is a 

 row of curved markings running in a nearly horizontal direction, 

 giving the appearance of a double border. There is, however, 

 more than a suspicion that there are a number of minute 

 openings all along the outer edge about the 1/1, 000th of an inch 

 apart, since the contraction of the balsam, and consequently the 

 increased pressure on the surfaces of the malleoli, has expressed 

 a number of globules of glycerine which look like a row of beads 

 ahing the margins of these particular specimens. 



Unless it be with the curious organ the pecten found on 

 the under side of the Scorpions, the malleoli seem to have no 

 analogy amongst the Arachnida, and the special purpose they 

 are intended to serve is one concerning which we certainly have 

 no actual knowledge. Some writers simply refer to them as 

 " sense organs," without risking any guess as to what that sense 

 may be, others have thought them to be organs of touch ; but 

 it would ill become us to restrict their use to anv one sense, 

 and merelv to assign them to a tactile sense which seems 

 amply provided for by the pedipalpi, the first pair of legs, and 

 the extended hairs with which every appendage is furnished. 



Experiments with the vibrations of light and of sound lead 

 one to the belief that there may be vibrations beside those to 

 which our own sense organs respond, and it may be that the 

 malleoli are tuned to vibrate in unison with such impulses, 

 onveying to the Solpuga information as to the whereabouts of 

 its fellows, its enemies, or its prey. 



The following preparations were exhibited in illustration of the 

 above paper: (1) Extremity of a pedipalp. (2) Extremity of 

 first leg, showing striated hairs. (3) Extremity of second leg, 

 .showing jointed claw. (4) Fourth leg, showing the malleoli in 

 position. (5) One of the malleoli, more magnified. (6) Hairs 

 from the inner surface of chelicerae. 



Journ. Quekett Microscopical Club, Ser. 2, Vol. XL, No. 71, November 1912. 



