PATAGONIAN EXPEDITIONS I ZOOLOGY. 



EXPLANATION OF PLATE XL. 



(VOL. in) 



PAGE 



Figs, i, 2, 2a. POTAMOLITHUS ORBiGNYi Pils. Cotypes, adult stage . 582 



Fig. 3. " " " Small individual ap- 



proaching the adult 



stage . . . 582 



Figs. 4, 40, 5. " " " Neanic stages . . 582 



Figs. 6, 6a, 6d. POTAMOLITHUS TRICOSTATUS (Brot). Threfe views of 



adult stage . 593 



Fig. 7. " " " Gerontic individ- 

 ual . . . 593 



Figs. 8, 9, 90. POTAMOLITHUS CONICUS (Brot). Adult stage. . . 581 



Figs. 10, loa. POTAMOLITHUS AGAPETUS Pils. Two views of the type . 578 



Figs, ii, i la. POTAMOLITHUS BUSCHII (Ffld.). Two views, neanic stage. 580 



Figs. 12, 120, 13, 14. " " " Adult individuals. . 580 



