694 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xx. 



Plate LXVIII. 



Fig. 1. Parastacus saffordi Faxon. Female. Montevideo, Uruguay. Somewhat 

 enlarged. (No. 12581, U.S.N.M.) 

 2. The same. Eight claw, from the outside. 



Plate LXIX. 



Fig. 1. Parastacus varicosus Faxon. Coliina, Mexico. Slightly enlarged. (No. 4133, 

 U.S.N.M.) 

 2. The same. Right chela, viewed from the outside. Slightly enlarged. 



Plate LXX. 



Fig. 1. Parastacus hassleri Faxon. Talcahuano, Chile. Somewhat reduced. (No. 

 3401, Mus. Comp. Zool.) 



2. The same. Right chela, viewed from the outside. Somewhat reduced. 



3. The same. Part of the sternum, showing sexual orifices on the proximal 



segments of the third and fifth pairs of legs. 



4. Parastacus agassizii Faxon. Male. Talcahuano, Chile. Somewhat reduced. 



(No. 3400, Mus. Comp. Zool.) 



5. The same. Part of the sternum, showing the extended rasa deferentia on 



the proximal segments of the fifth pair of legs. 



