634 CLASS x. 



feet, with short fleshy peduncle, and two cirri, multiarticulate, 

 horny. Mouth with mandibles and maxillae membranoso-horny. 

 Tail round, acuminate, reflected between the feet towards the ven- 

 tral surface of the animal. 



Comp. POLI Testacea utriusque Sicilice, I. pp. i T 39 ; CUVIER Memeires 

 sur les Animaux des Anatifes et des Balanes (Lepas L.) et sur leur anatomic; 

 Me"m. du Mus. d'Hist. nat. n. 1815; G. J. MARTIN ST. ANGE Memoire 

 sur T Organisation des Cirripddes. Avec i planches. Paris, 1835, 4to. ; H. 

 BURMEISTER Beitrdge zur Geschichte dcr RanJcenfiisser. Mit 2 Kupfert. Berlin, 

 1834, 4to. Catal. comp. Anat., coll. of Surgeons, i. PL iv. pp. 255 260, 

 Anatomy of Pentalasmis vitrea and Ealanus tintinnabulum. See also the 

 article Cirrhopoda by J. COLDSTREAM in TODD'S Cyclopaedia, i. 1836, pp. 

 683 694 : and especially DARWIN Monograph of tfte Cirripedia (Lepadidce), 

 London, 1851, and Monograph of the Cirripedia (Balanidce, Verrucidce, 

 &c.), London, 1854. 



With LINNJEUS these animals formed only a single genus (Lepas). 

 LAMAECK 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. Y. THOMPSON 2 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 Lernceacea to the Copepoda. 



Although the shells differ much in different species, and some of 

 these animals are pedunculated, others not, yet the cirripeds have 

 such an agreement in internal and external structure, that we have 

 every reason to admire the sagacity of LINNAEUS 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 Philosophic zoologique. Paris, 1809, i. pp. 314, 315. 



3 Zoological Researches, Cork (1830), and Philos. Transact, for 1835, pp. 355 35 8 > 

 PI. vi. 



