651 



to say whicli predominate ; yet the rays are there. In this species 

 there are no traces of them, but in the hinder part of the shell 

 they are strong and oblique, while in the front part there are 

 only concentric ribs. The colouring is arranged in pinkish spots. 

 Locality uncertain. 



6. Circe australis (pi. cxxxvii. f. 16, 17), Sowerbi/,jtm. 



Cir. postice subquadrata, costulis divergentibus, prope margi- 

 nem anticum costulis divergentibus brevibus, in medio costis 

 angularibus concentricis ; colore pallide fulvo, lineis divergentibus 

 et maculis fuscis ; intiis purpurascente-fusco nebulato, ad mar- 

 ginem nigro-punctato. 



Shell with diverging ribs and black lines at the back, concen- 

 tric ridges in the middle, and diverging short ribs near the an- 

 terior margin ; colour pale brown inside, clouded with purplish- 

 brown, with black spots at the edges. 



North-eastern Australia. 



Sect. 2. Testa rotundata, compressa, prope umhones et ad latera 

 divergenti-costata vel striata, varie fusco angulathn picta, 

 lunula distinctd. 



7. Circe scuiPTA (pi. cxxxix. f. 38, 39, 40, 41, 42, 43). 

 Venus scripta, Linn., Syst. Nat. p. 1135. Var. C. violacea, Sclmm. 



Cir. testa compressa ; costis concentricis numerosis ; margine 

 dorsali rectiusculo, elevato, subcomplanato ; lunula distiucta; 

 costulis divergentibus, prope umbones indistinctis. 



Shell rather fiat, with the liinder part broad and square ; dorsal 

 edge straight and elevated; concentric ribs numerous, particu- 

 larly at the back ; diverging rays near the umbones scarcely per- 

 ceptible. 



Red Sea and Australia. 



8. Circe undatina (pi. cxxxviii. f. 22, 23, 24, 25, 26). Cy- 

 thersea undatina, Lamarck, no. 56. 



Cir. testa C. scripta simili, sed magis ventricosa ; margine dor- 

 sali subarcuato, declivi ; costis majoribus, rotundatis. 



Shell more ventricose than C. scripta, the dorsal margin more 

 rounded and sloped downwards ; the ribs generally larger. Varia- 

 tions in colouring the same. 



Red Sea and Australia. 



