Class— CRUSTACEA. Sub-Class— CIRRIPEDIA. 



Family— LEPADID.E. 



Cirripedia pedunculo flexili, muscidis instruclo : scutis* 

 musculo adductore solummodd instructis : valvis cceteris, 

 siqum adsunt, in annulurn immobilem hand conjunctis. 



Cirripedia having a peduncle, flexible, and provided 

 with muscles. Scuta* furnished only with an adductor 

 muscle : other valves, when present, not united into an 

 immovable ring. 



Metamorphoses ; larva, first stage, of body, and muscular system, p. 



pp. 9 — 12; larva, second stage, 39; mouth, ib.; cirri, p. 42; cau- 



p. 13; larva, last stage, p. 14; dal appendages, p. 43 ; alimentary 



its carapace, ib. ; acoustic organs, canal, 44 ; circulatory system, 



p. 15 ; antennae, ib. ; eyes, p. 16; p. 46; nervous system, ib. ; 



mouth, p. 17 ; thorax and limbs, eyes, p. 49 ; olfactory organs, p. 



p. 18 ; abdomen, p. 19 ; viscera, 52 ; acoustic(?) organs, p. 53; male 



ib. ; immature cirripede, p. 20 ; sexual organs, p. 55; female organs, 



homologies of parts, p. 25. p. 56; ovigerous lamellae, p. 58; 



ovigerous fraena, ib.; exuviation, 



Description of mature Lepadidae, p. 61 ; rate of growth, ib. ; size, 



p. 28 ; capitulum, ib. ; peduncle, ib. ; affinities of family, p. 64 ; 



p. 31 ; attachment, p. 33; fila- range and habitats, p. 65 ; geologi- 



mentary appendages, p. 38 ; shape cal history, p. 66. 



Metamorjrfioses. — I will here briefly describe the Meta- 

 morphoses, as far as known, common to all Cirripedia, 

 but more especially in relation to the present family. 

 I may premise, that since Vaughan Thompson's capital 

 discovery of the larvae in the last stage of development in 

 Balanus, much has been done on this subject : this same 

 author subsequently published! in the ' Philosophical 

 Transactions, 5 an account of the larvae of Lepas and 

 Conchoderma (Cineras) in the first stage ; and seeing how 

 totally distinct they were from the larva of the latter stage 

 in Balanus, he erroneously attributed the difference to 



* The meaning of this and all other terms is given in the Introduction, 

 at pp. 3-7. 



T Philosophical Transactions, 1835, p. 355, PL vi. 



