SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE, VOL. XXXIII. PLATE 7. 
BIG. 7. FIG. 4. Fic. I, 
Fic. 2. 
FIG, 10, Fic. 8. FIG. 9. 
Fic. 5. Fic. 6. 
BALASNOPTERA PHYSALUS (L.), B. MUSCULUS (L.), AND B, VELIFERA CoPE (?). 
Fig. 1.—B. physa/us, Cape Cod, Mass., No. 16039 U.S. N. M. Figs. 2 and 4.—Di7¢to, No. 16045 U.S. N. M. Fig. 3.—&. velifera (?), California, 
Figs. 5, 9, 10.—B. musculus, Newfoundland. Figs. 6-8.—/Dif/o, Ocean City, N. J. 
