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Professor MacGillivray on the Cirripedia. 297 
situated near the lower edge of the aperture; the mantle open at 
the upper part only, and with the cuticle prolonged at the other end 
to form a fleshy peduncle; the branchie simple, tapering, at the 
base of the lower cirri. 
Lepas. BARNACLE. 
Animal subovate, compressed, gibboso-convex on the back, incurvate, 
with the mouth very prominent, and furnished with a pair of external, 
partially adnate palpi, and three pairs of incurvate, compressed, maxil- 
lary appendages, of which the thin terminal lamina is ciliated with spines 
or bristles ; the body narrowed behind, with twelve pairs of pedicellate, 
long, slender, incurvate, multiarticulate, lobulate, bifariously ciliate 
cirri; two unequal, slender, tapering branchial filaments on each side ; 
one from the base of the pedicle of the first pair of cirri, the other from 
the side of the body near it; the ovarian tube tapering, annulated, longer 
than the last cirri. 
Tegmen compressed, subovate, with two large calcareous plates on 
each side, and a single, elongated, curved dorsal piece; the aperture in 
the form of a slit, occupying the upper half of the ventral border; pe- 
duncle cylindrical, contractile, fleshy: its epidermic coat continuous 
with the tegmen ; its inner dermic tube continuous with the mantle or 
dermal lining of the tegmen, on the inner surface of which is a delicate 
layer of pigment. 
This genus being generally considered the typical group of the Barna- 
cles, or Pedunculated Cirripedia, it ought to give its name to the family. 
Linnzus’s genus Lepas is equivalent to almost the entire class, he having, 
in his Systema Naturee, only one other genus, containing a single species, 
and now generally named Alepas, but to which the priority-of-nomen- 
celature naturalists must restore its proper name Triton, which has been 
given to a genus of Batrachian reptiles, and also to a genus of Gastero- 
podous mollusca. The sessile species were first separated under the 
eneric name of Balanus, but now form a family, Balanina, of which 
alanus restricted is typical. To be consistent, the pedunculated spe- 
cies ought to have retained the name Lepas, agreeably to the practice of 
Montagu and others; and as they now form a family, it ought to be 
named Lepadina, of which Lepas restricted is typical. Bruguiere and 
Lamarck, however, call Lepas Anatifa, a specific Linnean name al- 
tered and mutilated. Dr Leach calls it Pentelasmis, and Blainville Pen- 
talepas ; in which cases, the family name should be Anatifina, or Penta- 
lasmina, or Pentalepina. As naturalists are not yet agreed as to nomen- 
elature, and the general meeting proposed some years ago, for the pur- 
pose of settling such important matters, has not yet taken place, isolated 
persons like myself must employ some such names as are intelligible. 
The Lepades, Anatifse, Pentelasmides, or Pentalepades, then, live 
affixed to wood, cork, bark, fuci, crustacea, fishes, and other bodies, as 
well as to each other, and to various pedunculate and sessile cirripedia. 
Their fleshy peduncle varies in length and colour, even in the same spe- 
cies. The tegmen also presents considerable differences as to the form, 
thickness, and markings of its pieces. They are more abundant in warm 
than in temperate climates, and rare in the colder regions, into which, 
however, they are often carried, by the currents and winds, along with 
the bodies to which they adhere. 
Of this genus three species have occurred: two of them long known, 
but very imperfectly described ; the other not hitherto observed, or at 
least distinguished, in our seas. 
