U. S. NATIONAL MUSEUM. 



BULLETIN 100, VOL. 2, PART 3, PL. 33 



Fig. 42 







Fig. 43 



PYROSOMA AGASSIZI (FIG. 42); P. VERTICILLATUM CYLINDRICUM (FIG. 43); P. ELLIPTICUM (FIG. 44). 

 For explanation of plate see page 272. 



