ALC1PPE LAMPAS. 559 



the lower end of the peduncle, the whole inside of the animal 

 being thus freely open to the water. In the upper part, the 

 sack forms a mere narrow tube ; it does not appear to have 

 been formed in the same manner as in all other cirripedes, 

 namely, surrounding the thorax and natatory legs of the 

 pupa, but in an abnormal position, along the dorsal surface, 

 above the sack and thorax of the pupa : a transparent line, 

 where the new narrow sack is in process of formation, is 

 the first indication of the coming metamorphosis. The 

 sack in the capituium of the male is not central, but lies 

 near the dorsal surface ; the ventral interspace, between 

 the outside and the sack, is occupied by oblique fibres 

 (/, fig. 19), which may be strise-less muscles, but I sus- 

 pect are ligamentous fibres, giving support to the whole 

 projecting capituium. These fibres enter a little way 

 within the lobed peduncle ; they are probably homologous 

 with the strong muscles, which run from beneath the 

 upper end of the horny disc of the female to the lower end 

 of the orifice leading into the sack. Round the lobed 

 peduncle,* there are two bands (e,f) of thin muscular 

 fasciae, slightly oblique to each other, and attached at the 

 ends to the outer membrane; they are evidently homologous 

 with the external transverse muscles, which are best de- 

 veloped round the same part in the female. Some of these 

 muscles present a singular chain-like appearance, from being 

 strangled at intervals : they act probably in aiding the long 

 probosciformed penis to protrude itself out of the sack. I 

 could not detect any longitudinal muscles, and the lower 

 part of the peduncle seems destitute of muscles of any kind. 

 The internal structure of the animal is very simple. 

 Within the lower end of the peduncle there is a dark purple 

 eye (c), under the ^th of an inch in diameter, a testis (d) 

 and a (5) vesicula seminalis. These organs falsely appear as if 

 suspended in the middle of the peduncle, but they are really 

 attached, I believe within a separate partition, to the 

 ventral surface, occupying the same position as the mass of 

 ovarian casca in the female. The eye lies on the line of 

 junction between the testis and the vesicula seminalis, and 



* I believe I saw in one specimen, most delicate transverse muscular fibres 

 round the lower part of the elongated capituium. 



