THE SESSILE BARNACLES. 



93 



ing. Spur sliort, its \^'idlll over one-tliird that of the base; crests 

 for depressor nuiscles sirongly developed, projecting below the basal 

 margin. 



The labrum has tlu-ee teeth on each side, one witliin 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. Ide). 



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



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

 upper and lower pairs of large spines (fig. 19&). 



First ciiTus of 18 and 12 segments, tlie posterior ramus two-tliirds 

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



Fio. 19. — Balanus AMPniTRiTE im'Eus, Marco, FLOKroA. a, Segment op cirrus m. b, 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-fourlhs as long as the anterior. Cirrus iii with the 

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

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

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

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

 is two or three segments lons^er than the inner. The succeeding 

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

 of spines, a few median segments having a minute sixth pair (fig. 19(Z). 

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

 figs. 2-2e). 



Tlie definition of subspecies of B. amj)Mtnte is a very intricate 

 problem, domanfling more time and material than I can connnand, 



