124 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



Cirrus iii has unequal rami, not longer than those of cirrus ii, of 

 14 and 8 segments. All but the lower and terminal segments of 

 both rami bear recurved "teeth" as in figure 33a. These teeth are 

 fewer on the inner ramus and on the distal segments of the outer. 

 Near the base there are some flat multifid scales around the anterior 

 patch of long spines (fig. 331), The anterior-distal angles of the seg- 

 ments of the pedicel bear some minute, marginal spinules. 



Gurus iv has the outer ramus armed with recurved teeth (fig. 

 33c). In the lower part there are up-curved teeth on the posterior 

 border. Farther out these disappear, and the great posterior spine 



FIG. 33. BALANUS PERFORATES, NAPLES, a, IOTH SEGMENT OF ANTERIOR RAMUS OF CIRRUS in. 



6, 6TH SEGMENT OF ANTERIOR RAMUS OF CIRRUS in. C, 7TH SEGMENT OF THE ANTERIOR RAMUS OF 

 CIRRUS VI. 



is replaced by two smaller ones, finally by several much smaller. 

 The inner ramus has no anterior "teeth," but there are posterior 

 teeth as in the other ramus. It has six pairs of spines on the seg- 

 ments. The segments of the pedicel have no spinules in the fourth 

 to sixth cirri. 



Cirrus v is like the inner ramus of cirrus iv. The outer ramus has 

 teeth on the posterior margin toward the base. Cirrus vi has seg- 

 ments much longer than wide, bearing six pairs of spines, which are 

 pectinated toward the ends. The lower segments of both rami are 

 copiously provided with short, up-curved " teeth" along their pos- 

 terior margins. These teeth gradually become fewer upward. 



The penis is longer than cirrus vi and has an acute basi-dorsal 

 point. 



