Professor MacGillivray on the Cirripedia, 173 



Generally, in very small individuals, the dorsal piece projects beyond the 

 upper two, which meet it, and seem as if articulated to it. In older 

 individuals, there is often a considerable space between the summit of 

 the dorsal piece and the upper pieces, which are more or less divergent 

 at the base. These upper pieces are straight, recurved, twisted, linear, 

 or broader at the basal end, sometimes incurved or recurved at the 

 outer. The dorsal piece is nearly straight in very young, often much 

 curved in old, individuals. The fork of the ventral pieces is very con- 

 spicuous in young individuals, more or less filled up in old. 



Many individuals, large and small, were of a light-brown or yellowish- 

 grey colour, with irregular brown streaks, or crowded dots ; but in other 

 respects not different. 



Individuals of this species, in all stages, were found in vast pro- 

 fusion, on three of the vessels, adhering to the wood, to pitch, or to 

 each other, and to the Otions and Lepades. 



Were characters derived from the precise form of the calcareous 

 pieces, and from the colours of the tegmen and peduncle, to be as- 

 sumed, as availing for specific distinction, half a dozen species might 

 easily be formed out of this. 



The following references are pretty certain :— 



Lepas membranacea. Mont. Trans. Linn. Soc. xi. 182, plate 12, fig. 2. 



Lepas membranacea. Turt. Conch. Diet. 73. 



Lepas coriacea. Poll. Test. i. plate 6, fig. 20. 



Cineras vittata. Leach. Encyclop. Brit. Suppl. iii. 170, plate 57. 



Cineras vittata. Lamk. Anim. s. Vert. v. 684. 



Cineras vittata. Gould, Invert. Massach. 22. 



Cineras bicolor. Hiss. Eur. Mend. iv. 383. 



Gymnolepas Crouchii. Blainv. Malac. plate 84, fig. 2. 



Dimensions of several individuals :— 



OrioN-. Eared Barnacle. 



Animal oblong, little compressed, gibboso-convex on the back, incur- 

 vate, considerably prolonged anteriorly, with the mouth very prominent, 

 and furnished with a pair of external, partially adnate, pointed palpi, 

 and three pairs of incurvate, compressed, maxillary appendages, of 

 which the thin terminal lamina is ciliated with spines or bristles ; the 

 body narrowed behind, with twelve pairs of pedicellate, long, tapering, 

 incurvate, multiarticulate, lobulate, ciliate cirri ; the ovarian tube taper- 

 ing, annulated, longer than the last cirri ; three branchial filaments at 

 the base of the first foot, and one on several of the rest on each side. 



Tegmen cuculllform, cylindracco-globose, coriaceous, smooth, with five 

 distant, verj' small, calcareous pieces ; two oblong, geniculate or angii- 

 late, at the lower margin of the aperture ; two linear at the summit ; and 

 aa extremely small dorsal; at the top, behind the aperture, two large, 



