ANELASMA SQUALICOLA. 175 



extent, probosciformed, and being curved a little down- 

 wards, projects slightly over the adductor muscle, to 

 which it is closely placed. The labrum does not project 

 more beyond the general surface of the body, than in 

 many other Cirripedes, but the probosciformed structure 

 is caused by the elongation of the surface fronting the 

 thorax. The summit of the mouth stands above the level 

 of the top of the pedicels of the first pair of cirri. The 

 labrum is slightly hollowed out in the middle of its upper 

 margin ; it can scarcely be called bullate, in which it 

 differs from all other Lepadidse; on the other hand, the 

 outer and inner folds of the labrum are not so close 

 together as in Balanus. On each upper corner, there is, 

 as usual, a small rounded prominence, close to which 

 there is a second slight, rounded, spineless swelling ; 

 these latter represent the quite rudimentary Palpi. 



The Mandibles (figs. 4, 5) are more highly developed 

 than the other tropin ; they are, however, very minute, the 

 toothed edge being only about -j-J-Jb- th of an inch in length, 

 measured in its longest direction ; the edge is unusually 

 thick, with the teeth placed rather on one side ; this organ, 

 when viewed on the labrum side (fig. 5), shows two large 

 teeth placed low down, with the inferior angle pectinated 

 and broadlv truncated : but when viewed on the other or 

 maxillae side (fig. 4), several large and small teeth, placed 

 alternately and irregularly in pairs, are seen extending 

 along the whole edge. The mandibles are furnished, as 

 usual, with three principal sets of muscles attached to the 

 basal fold of the mouth. 



The Maxilla (fig. 7) are still smaller than the man- 

 dibles; the spinose edge being only the -^th of an inch in 

 length ; the edge, instead of being square, and furnished 

 with a double row of long spines, as in all other Cirripedes, 

 is rounded, thick, club-shaped, and with the side facing the 

 mandibles, thinly and irregularly strewed with short, thick, 

 very minute spines ; there is a large broad apodeme (a), 

 in the usual place, but it is much more transparent and 

 flexible than common : there are also the usual muscles. 



