CLITIA. 



Leach, 



TESTA compresso-subconica, basi affixa; valvis 

 quatiior, insequalibus, duabus majoribus, diia- 

 bus minoribus, lateraliter intertextis eomposita; 

 apertura trapeziformi, operculo bipartito 

 clausa, Valvis operculi, altera irregulariter 

 tetragona, altera subtrigona. 



Distinct from Creusia, although the external shell in both 

 consists of four pieces. In this the four pieces are irregu- 

 larly unequal, and the operculum, moreover, consists^of 

 only two pieces which are also unequal. 



This is the Lepas striata of Pennant, L. Verruca of 

 Gmel., and it not unaptly resembles a small warty excres- 

 cence adhering to the outside of other shells, &c. Two 

 recent species only have occurred, one of which is common 

 on our own coasts, the other has only lately been brought 

 from the coast of South America adhering to Mytilus 

 magellanicus, and to other shells. 



Shell of a very flattened conical form, irregular, 

 adhering by the base, composed of four unequal valves, 

 two larger and two smaller, laterally joined together by 

 the interlocking of their dentated edges; none of these 

 valves are exactly alike \ the aperture is rather laterally 

 placed, trapeziform, and entirely closed by a bipartite 

 operculum, one of whose pieces is irregularly quadrate, and 

 the other nearly triangular. 



Of the two species we have selected for our illustra- 

 tion that which has not yet been described, it diff^ers from 

 the common European species, of which we have also 

 given a magnified representation, in the outside of the 

 valves being smooth, whereas in CI. Verruca they are 

 striated : we call it CI. Icevigata: the two species may be dis- 

 tinguished by the following diagnosis. 



1, Cl. Verruca, testsi valvis externa rugosis. 



Syn. Lepas Verruca, Gmel. et nonnull. 

 Lepas striata, Pennt. et nonnull. 

 Balanus intertextus, Pult. 

 Creusia, Lam. 



Obs. Evidently placed by Lamarck as a species of Creusia. 



2. Cl, l<evigata, test^ valvis externe Itevigatis. 



