THE 



BARNACLES. 



93 



ing. Spur short, its width over one-third that of the base; crests 

 for depressor muscles strongly developed, projecting below the basal 



margin. 



The labrum has three teeth on each side, one within the notch 

 (fig. 19/). Labral palpi have two rows of spines, one of numerous 

 small ones, the other of long spines; also the usual dense terminal 

 covering of spines and bristles (fig. 19c). 



The mandible has the two lower teeth short and blunt. (Fig. 19c.) 



Maxilla with a nearly straight edge, and five spines between the 

 upper and lower pairs of largo, spines (fig. 106). 



First cirrus of IS and 12 segments, the posterior ramus two-thirds 

 the length of (he anterior, and having strongly protuberant segments. 



FIG. 19. BALANUS AMPHITRITE NTVETTS, MARCO, FLORIDA, a, SEGMENT OF CIRRUS m. 6, MAXILLA. 



C, MANDIBLE, d, INTERMEDIATE SEGMENT OF CIRRUS VI. e, PALPUS. /, LABRUM. 



Cirrus ii of 13 and 11 segments, strongly protuberant, the posterior 

 ramus three-fourths as long as the anterior. Cirrus iii with the 

 anterior, outward part of the lower nine segments thickly set with 

 short, conic, decurved teeth (fig. 19a); the inner faces of these seg- 

 ments having long spines, not shown in the figure. The posterior 

 margins of the segments are also shortly spinose. The outer ramus 

 is two or three segments longer than the inner. The succeeding 

 cirri are much alike. Cirrus vi has 28 segments bearing five pairs 

 of spines, a few median segments having a minute sixth pair (fig. IQd). 

 The above description is from specimens from Marco, Florida (pi. 19, 

 figs. 2-2e). 



The definition of subspecies of B. ampliitrite is a very intricate 

 problem, demanding more time and material than I can command, 



