U. S. NATIONAL MUSEUM. 



BULLETIN 100, VOL 2, PART 3, PL 34. 



Fig. 45 



Fig. 46 



Fig. 47 



PYROSOMA ATLANTICUM ATLANTICUM (FIGS. 45 AND 46); P. ATLANTICUM FORM DIPLEUROSOMA (FIG. 47). 



For explanation of plate see page 272. 



