300 Professor MacGillivray on the Cirripedia. 
Of the descriptions of Anatifa levis or Lepas anatifera given by authors, 
those which agree best with our specimens are by Philippi and Dr Gould. 
Cuvier’s figure differs a little, and his specimens must have been much 
older. His figures of the structure are very rude, and those of the cirri 
in particular very incorrect. 
The following references are all which I can apply to this species, as 
it presents itself on the Ichaboe vessels :— 
Lepas anatifera. Linn. Syst. Nat. 1109. Very probably. 
Lepas anatifera. Chemn. Conch. viii. 340, plate 100, fig. 853-4-5. 
Lepas anatifera. Penn. Brit. Zool. iv. 74, plate 38. fig. 9. 
Lepas anatifera. Turt. Conch. Dict. 71. Excluding his varieties, 
which yet belong to the same species. 
Anatifa levis. Lamk. Anim. sans Vert. v. 404. 
Anatifa levis. Gould, Invert. Massach, 19, woodcut p. 11. 
Anatifa levis. Philippi, Moll. Sicil. 252. 
Anatifa levis. Brown, Illustr. plate 4, fig. 3, 4. 
Lepas anatifera. Donov. Brit. Sh. plate 7. 
Lepas anatifera. Mont. Test. Brit. 15. 
Pentalepas levis. Blainv. Malac. plate 84, fig. 3. 
The following are the dimensions of several individuals :— 
Length, . : 1 4 L°'6 a eee} a ig 0 6 
Depth, . : 0 10 S Epa 0) 0 94 0 8 0 3} 
Breadth, . : 0 33 0 32 0 3 0. 2 ate 
Peduncele, ienG PIN) ie?) 0 6 0 4 
2. Lepas Nauta. Sailor Barnacle. 
Tegmen ovate, compressed, obliquely truncate; the lateral plates rather 
thick, bluish-white, glossy, obsoletely rugose, with distinct radiating 
striule ; the lower plate subtriangular, with the basal margin very 
oblique, straight, the posterior half its length and convex, the sutural 
straight, the apex rather acute; the upper plate oblong, subrectangular 
at the tip, narrow, and rather acute at the lower end, the supraumbonal 
side of about the same length as the anterior ; the dorsal piece linear- 
lanceolate, carinate, deeply sulcate, extending to more than half the 
length of the upper lateral piece, abruptly inflexed at the base; the pe- 
duncle rugose, dusky-brown, the epidermic portion of the tegmen scar- 
let or orange ; the cirri greyish-brown. 
The body of the animal is ovate, compressed, incurvate, very convex 
on the back, narrow behind ; anteriorly soft, with a membranous integu- 
ment which becomes horny on the hind part. The mouth prominent, 
with an induplicate or vaulted, bullate, rounded lip, with two thick ad- 
nate palpi, free at the end, where they are conico-compressed, and end 
in a long incurvate, acute prickle, and three pairs of incurvate, com- 
pressed, maxillar appendages. The first or outer pair with the terminal 
lamina oblong, acute, with six external marginal, acuminate teeth or 
serratures, of which the posterior is much larger, the rest gradually de- 
creasing. The second with the lamina broad, with five short, broad 
teeth, and ciliate. The third or inner narrower, pointed, and ciliate. 
The first pair of feet close to the mouth, with the cirri unequal, of 
about 15 joints ; the rest crowded, the last with 45 joints; all ciliate, 
with long unequal bristles in two series, generally from 12 to 16 on each 
lobe. 
Two branchial tapering filaments on each side, the longer attached to 
