651 



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

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

 they arc 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), Soiverhy, jun. 



Cir. postice subquadrata, costulis divergcntibus, propc margi- 

 nem anticum costulis divergentibus brevibus, in medio costis 

 angularibus concentricis ; colore pallkle fulvo, lineis divergentibus 

 et maculis fuscisj intus 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 umbones et ad latera 

 divergenti-costata vel striata, varie fusco angulation picta, 

 lunula distinctd. 



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

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



Cir. testa compressa ; costis concentricis numerosis ; margine 

 dorsali rectiusculo, elevato, subcomplanato ; lunula distincta; 

 costulis divergentibus, prope umbones indistinctis. 



Shell rather flat, with the hinder 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 Austraha. 



8. Circe undatina (pi. exxxviii. 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. 



