634 CLASS xX. 
feet, with short fleshy peduncle, and two cirri, multiarticulate, 
horny. Mouth with mandibles and maxille membranoso-horny. 
Tail round, acuminate, reflected between the feet towards the ven- 
tral surface of the animal. 
Comp. Por1 Testacea utriusque Sicilia, 1. pp. 11—39; Cuvier Mémoires 
sur les Animaus des Anatifes et des Balanes (Lepas L.) et sur leur anatomie ; 
Mém. du Mus. d’ Hist. nat. uw. 1815 ;—G. J. Martin St. ANGE Mémoire 
sur UOrganisation des Cirripéedes. Avec 2 planches. Paris, 1835, 4to. ;—H. 
BuRMEISTER Beitriige zur Geschichte der Rankenfiisser. Mit 2 Kupfert. Berlin, 
1834, 4to.—Catal. comp. Anat., coll. of Surgeons, 1. Pl. Iv. pp. 255—260, 
Anatomy of Pentalasmis vitrea and Balanus tintinnabulum. See also the 
article Cirrhopoda by J. CoLpsTREAM in Topp’s Cyclopedia, 1. 1836, pp. 
683—694: and especially DAaRwin Monograph of the Cirripedia (Lepadide), 
London, 1851, and Monograph of the Cirripedia (Balanide, Verrucide, 
&c.), London, 1854. 
With Linnaus these animals formed only a single genus (Lepas). 
LAMARCK was the first who made of them a distinct class, to which, on 
account of the filiform arms, he gave the name of Cirrhipedes (cirri- 
pedes’). “Most writers place them amongst the molluscs, although 
the resemblance to articulate animals was apparent to many, and 
Cuvier shewed himself not averse to the opinion that they ought 
perhaps to be arranged amongst these. The history of their develop- 
ment, however, illustrated by J. V. THompson® and BURMEISTER, can 
leave no reasonable doubt that the cirripedes belong to the articulate 
animals, and amongst them do not form a distinct class, but only an 
order of the crustaceans. The place alone, which we allot them in 
the series of the crustaceans, may perhaps admit of some doubt, but 
we think that it ought to be preferred to a position at the end of 
the crustaceans, which determines nothing respecting their true 
affinity. According to us the Cirripedia have the same relation to 
the Daphnidea and Phyllopoda as the Lerneacea to the Copepoda. 
Although the shells differ much in different species, and some of 
these animals are pedunculated, others not, yet the cwripeds have 
such an agreement in internal and external structure, that we have 
every reason to admire the sagacity of Linnaus who united them 
all in a single genus. 
The body of these animals is in the adult state inarticulate, 
although on the dorsal surface, between the different pairs of feet, 
1 Philosophie zoologique. Paris, 1809, I. pp. 314, 315. 
2 Zoological Researches, Cork (1830), and Philos. Transact. for 1835, pp- 355—358, 
Pl. vi. 
