PATAGONIAN EXPEDITIONS : ZOOLOGY. 



Figs. 

 Figs. 



Fig. 

 Fig. 



Figs. 

 Figs. 



1, la, \b. 



2, 2a, 2d, 



4- 

 5- 



6, 6a. 



7, 7a, lb. 



o- 



Fig. 8. 



EXPLANATION OF PLATE XXXVIII. 



PoTAMOLiTHUS RUSHii Pils. Adult Stage. Type 

 PoTAMOLiTHUs MICROTRAUMA Pils. Type and a smaller 



specimen ........ 



PoTAMOLiTHus RUSHII Pils. Neanic stage, diam. 3 mm. 

 PoTAMOLiTHUS DiNOCHiLUS Pils. Adult, seen obliquely 



from above ........ 



POTAMOLITHUS HATCHERI Pils. Type. 



PoTAMOLiTHUS DINOCHILUS Pils. Three views of the type 

 (fig. 5 represents the same specimen) 



POTAMOLITHUS DINOCHILUS Pils. 



Neanic stage. 



PAGE 



599 



597 

 599 



595 

 594 



595 

 596 



(vol. hi) 



