PATAGONIAN EXPEDITIONS I ZOOLOGY. 



EXPLANATION OF PLATE XL. 



PAGE 



Figs. I, 2, 2a. PoTAMOLiTHUS ORBiGNYi Pils. Cotypcs, adult stage . 582 

 Fig. 3. " " " Small individual ap- 

 proaching the adult 



stage . . . 582 



Figs. 4, 4^:, 5. " " " Neanic stages . . 582 

 Figs. 6, 6a, 6b. Potamolithus tricostatus (Brot). Three views of 



adult stage . 593 

 Fig. 7. " " " Gerontic individ- 

 ual . . . 593 

 Potamolithus coNicus (Brot). Adult stage. . . 581 

 Potamolithus AGAPETUS Pils. Two views of the type . 578 

 Potamolithus BuscHii (Ffld.). Two views, neanic stage. 580 

 " " " Adult individuals. . 580 



(vol. in) 



