AKTEMIS.— Plate IV. 



in lamellffiform scales before reaching the edge of the shell. 

 The coloured rays constitute also a characteristic feature in 

 this comijaratively colourless genus. 



Species 33. (Mus. Cuming.) 



Artejiis prosteata. Art. testa, qmdratu-orhicidari, 

 valde depressd, coiicentrice liratd, liris ad latera irre- 

 gulmiter convergentibm et corrugatis, marginem versus 

 lamellaribns et squamatis, area ligamenti suhexcavatd, 

 lunula elongato-cordatd ; sordidefulvd. 



The flattened Aktemis. Shell squarely orbicular, 

 very depressed, concentrically ridged, ridges con- 

 verging irregularly at the sides and wrinkled, lamellar 

 and squamate towards the margin, area of the 

 ligament slightly excavated, lunule dongately cordate; 

 duU fulvous colour. 



Venus prostrata, Linnaeus, Syst. Nat. (12th. edit.) p. 1133. 

 Euc. Meth.pl. 277. f.l". 



Hab. Mouth of the Swan River, New Holland ; Collie. 



Peculiarly inclined to grow square, and further charac- 

 terized by the irregular converging together and wrinkling 

 of the ridges. 



Species 24. (Mus. Cuming.) 

 Artemis corrugata. Art. testa suborbiculari, aliqicanio 

 latlore quam altd, tentii, convexd, concentrice striatd, 

 striis in medio fere obsoletis, ad latus posticum Uras 

 convergentes et corrugatas formantibus, ad latus anti- 

 cutn minus elevatis, longitudhialiter lineis indentatis 

 obsolete radiatd, area ligamenti simpUci, lumdd snb- 

 oblongo-cordatd ; so7-dide spadiceo-albd. 



The wrinkled Artemis. Shell nearly orbicular, a 

 little broader than high, thin, convex, concentrically 

 striated, striaB almost obsolete in the middle, forming 

 wrinkled and converging ridges at the posterior side, 

 much less elevated on the anterior side, longitudinally 

 obsoletely rayed with indented lines, area of the 

 ligament simple, lunule oblong-cordate ; dull fawn 

 white. 



Eah. ? 



A light, thin species, with a greater difference between 



the sculpture of the middle and sides of the sheD than 



usual. 



Species 25. (Mus. Brit.) 



Artemis c^kulea. Art. testa orbiculari, medio convexo- 

 twnidd, postice subangulatd, crassd, concentrice sub- 

 tiliter elevato-striatd, area ligamenti sublate excavatd, 

 limuld cordatd ; albidd, umbones versus rosacea et 

 caruleo tinctd. 



The blue-tinged Artemis. Shell orbicular, convexly 

 tumid in the middle, posteriorly slightly angled, 

 thick, concentrically finely elevately striated, area of 

 the ligament rather broadly excavated, luuule cordate ; 

 whitish, tinged with pink and blue towards the 

 umboes. 



Hab. Eaines' Island, ToiTes Straits ; Captain luce. 



A solid species, in which the concentric stria; are not 

 more prominent at the sides than elsewhere ; whilst the 

 delicate pink and blue colouring about the umboes is 

 characteristic. 



