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PROCEEDINGS OF THE NATIONAL MUSEUM 



tarsus of the male gonopod, and the somewhat flattened and massive 

 secondary tibiotarsus, its distal half twisted about 90 degrees to the 

 basal half. The cyphopod resembles that of P. c. hubrichti but lacks 

 the cluster of tubercules on the side of the receptacle. 



Variation : The male specimen from Men tone, Ala., agrees closely 

 with the holotype in gonopod structure as well as other details. The 



Figure 12. — Distribution of the known forms of Pachydesmus. Solid triangle, P. clarus; 

 hollow triangle, P. crassicutis crassicutis; hollow dot, P. c. duplex; hollow square, P. c. 

 denticulatus; inverted hollow triangle, P. c. incursus; solid square, P. c. adsinicolus; solid 

 inverted triangle, P. c. laticollis; half-shaded dot, P. c. hubrichti; solid dot, P. c. retrorsus; 

 symbol X, intermediate populations. 



apex of the secondary tibiotarsus is directed distad, instead of slightly 

 oblique, and the subterminal process is concealed in mesial aspect. 

 These minor departures, however, are little more than individual 

 variations. Farther south in Alabama, the gonopods become more 

 definitely intermediate between tliose as figured for retrorsvs and 

 hubrichti. The male at hand is 74 mm. in length and 15 mm. in 

 width; the female from Georgia is 69 mm. in length. 



