630 
THE AMERICAN NATURALIST. 
EXPLANATION OF PLATE II. 
Camera drawings of rostra. 
(Leitz, Oc. 1; Zeiss Obj. A,* IT.) 
Fics. 2-5. Male rostra. 
Fic. 2. Normal, 6 dorsal, 3 ventral spines. 
s uu 
Fic. 8. Normal, 6d. 3v. (sixth dorsal broken). 
Normal, 7d. 5v. 
Fic. 10. Small irregularities in 
Fn II. position of spines, 7d. 3v. 
Fic. 12. Normal, 7d. 4v. 
FiG. 13. Third ventral bifid, 8d. 
Fic. 14. 10d. 3v. irregular Sesion of spines. 
. EVOL. XXXIV. 
