ORDER I. SESSILES. 21 



PI. VII. Fig. 3. (fossil). 



Balanus circinatus, Defrance. Sowerby, Genera of Shells, No. 12. 

 Lamarck, Anira. sans vert , new edit., vol. v. p. 666. 



PI. VII. Fig. 4 and 5. 



Balanus Montagui, Sowerby, Genera of Shells, No. 12. 



De Blainville, Manuel de Malacologie, p. 597. pi. 85. f. 3. 

 Acasta Montagui, Leach. 



PI. VII. Fig. 6 to 8. 



Balanus galeatus, Lamarck, Anim. sans vert., new edit., vol. v. 



p. 664. 

 Conoplea elonyata, Say. 



CLITEA, Leach. 



Testa compresso-conoidea, valvis quatuor insequalibus, duabus majon- 

 bus, duabus minoribus, lateraliter intertextis composita ; apertura 

 trapeziformi, operculo bipartito clausa. Valvae operculi, altera irre- 

 gulariter tetragona, altera subtrigona. 



Dr. Leach, whose minute investigation of the Lepades is entitled to the 

 greatest attention, was the first to propose this genus ; it is the Lepas 

 verruca of the old authors, and was erroneously placed by Lamarck with 

 the CreusuB. Its shell is small, composed of four unequal pieces, inter- 

 dented together at the sides. The operculum is bipartite, one part quad- 

 rangular, the other nearly triangular. 



Examples. 

 PL VIII. Fig. 1 and 3. 

 Clitea laevigata, Sowerby, Genera of Shells, No. 33. 



