F. A. POTTS 



PLATE 2 



" 





Peltogasterella socialis, Kriiger. 



Figs. 5, 6, and 7. Stages in growth of the external sacs of Peltogasterella socialis, on Pagurus alaskensis. x 2. 

 Friday Harbour, San Juan Archipelago, State of Washington, U. S. A. 



