U. S. NATIONAL MUSEUM. 



BULLETIN 100, VOL 2, PART 3, PL 36. 



Fig 50 



Fiq 53 



Fig. 51 



Fig. 52 



Fig 55 



PYROSOMA ATLANTICUM, SUBSPECIES DOUBTFUL (FIGS. 50 AND 52); P. ATLANTICUM ATLANTICUM 

 (FIG. 53); P. HYBRIDUM (FIGS. 54 AND 55). 



For explanation of plate see page 272. 



