FISSUEELLA— Plate I. 



Deshayes, Enc. Meth. vers, vol. ii. p. 138. Anim. sans 

 vert. vol. vii. p. 601. 

 Fissurella Mediterranean Gray. 

 Hab. Mediterranean. 



The shell in this species is lilted up in the centre behind 

 the orifice, which is situated on the anterior declining 

 slope, and has a corresponding depression in the interior. 

 About twenty of the radiating ridges are more prominent 

 than the rest, and the basal margin is finely crenulated in 

 a bifid manner. 



Until the species was distinguished by M. Deshayes, in 

 the Encyclopedie Methodique, it was probably confounded 

 with the T. Orecca. 



Species 4. (Mas. Cuming.) 

 Fissurella crassa. Fiss. testa oblongo-ovatd, depresso- 

 convexd, ad utrmnque latus ^ubattenuatd, crassa, con- 

 centrice rude striata, margine inaquali, orificio oblomjo, 

 limbo 'peculiariter excavato, lateribus valde coarctatis, 

 quasi dentatis; flavido-fitscd, obscure nigricante radiatd, 

 intus cornigatd et palliSe rosacea. 



The thick Fissurella. Shell oblong-ovate, deeply con- 

 vex, slightly attenuated at tbe sides, thick, concen- 

 trically rudely striated, uneven at the margin, orifice 

 oblong, peculiarly excavated round the edge, very 

 much contracted at the sides, as if toothed ; yellowish 

 brown, obscm-ely rayed with black, wrinkled and 

 pinkish in the interior. 



Lamarck, Anim. sans vert. (Deshayes' edit.) vol. 7. p. 592. 

 Fissurella clypeiformis, Sowerby. 

 An eadem ? F. depressa, Lamarck. 



Hab. Valparaiso (on rocks at low water) ; Cuming. 

 M. Deshayes has some doubt of this being Lamarck's 



F. crassa, but it answers with remarkable accuracy to his 



description of that species. 



Species 5. (Mus. Cimiing.) 



Fissurella lata. Fiss. testd orbicidari-ovatd, antice vix 

 atlenuatd, elevatiusculd, radiatim obtuse liratd, liris 

 inaqualiter nodosis, orificio parvo, lateribus subexca- 

 vato ; olivaceo-cineras'cente, intense ptirpureo-roseo ra- 

 diatd. 



The broad Fissurella. Shell orbicularly ovate, very 

 slightly attenuated anteriorly, rather elevated, radiately 

 obtusely ridged, ridges unequally nodose, orifice small, 

 a little excavated at the sides ; olive-ash, rayed with 

 dark piu'ple-rose. 



Sowerby, Pro. Zool. Soc, 1834., p. 124. Conch. Illus. f. 63. 



Hah. Island of St. Mary, Chili, (in exposed places on the 

 rocks at low water) ; Cuming. 



This approaches rather to the F. maxima than to F. 

 picta, with which Ml". Sowerby compares it, but may be 

 readily distinguished from either. 



Species 6. (Mus. Cuming.) 



Fissurella picta. Fiss. testd omtd, elevatiusculd, ra- 

 diatim liratd, liris rudibus angustis, interdum nodosis, 

 iuterdum fere obsoletis, orificio oblongo-ovato, suban- 

 g/isto, lateribus vix excavatis ; cinerascente-albd, pur- 

 pureo-mgro Uneari-radiatd, circa aperturam cretaceo- 

 albd. 



The painted Fissurella. Shell ovate, rather elevated, 

 radiately ridged, ridges rude, narrow, sometimes 

 nodose, sometimes almost obsolete, orifice oblong- 

 ovate, rather narrow, sides slightly excavated ; ash- 

 white, radiated with lines of purple-black, chalk-white 

 around the aperture. 



Lamarck, Anim. sans vert. (Deshayes' edit.) vol. 7. p. 590. 

 Patella picta, Gmelin. 



Hah. Strait of ILigalhaens ; Falkland Islands. 



It is not improbable that two or three species have been 

 referred by diS'erent authors to the Patella picta of Gmelin. 

 Lamarck's description of its purple-violet colouring may 

 have been taken fi'om a worn specimen, to which the rich 

 dark painting of the specimen here represented would no 

 doubt have turned upon exposm-e to the weather. 



Species 7. (Mus. Cuming.) 



Fissurella Darwinii. Fhs. testd ovatd, antice subat- 

 tenuatd, tenuiculd, infra summitatem leviter compressd, 

 radiatim liratd, liris tenuibus, creiris, subundatis, 

 orificio oblongo-ovali ; superne alba, basin versus 

 intense cinered, nigra Uneari-radiatd, fasciis albis aut 

 perpaucis aut pluribus radiatd. 



Darwin's Fissurella. Shell ovate, a little attenuated 

 anteriorly, rather thin, slightly compressed below the 

 summit, radiately ridged, ridges thin, close-set, 

 slightly waved, orifice oblong-oval ; white at the 

 upper part, dark ash towards the base, radiated with 

 black lines, and more or less with white bands. 



Hah. Straits of Magalhaens ; Darwin. 



An interestiug new species of which several specimens 

 were collected by Mr. Darwin in the above-named locality. 



