126 THE VOYAGE OF H.M.S. CHALLENGER 



Animal. — The colour is pale and uniform : the eyes are large aud black, on short pro- 

 cesses. There are no frontal lappets between the tentacles, and though the forehead is 

 thickened there and transversely wrinkled, there is no veil. The usual fringed membrane 

 extends backwards above the foot-edge to the front of the operculum, but bears no threads. 



Shell. — Low, conical, round, with expanded base, sculptured, solid. Sculpture : The 

 whole shell is cross-hatched by narrow, impressed, intersecting lines, which cross the 

 whorls obliquely and not quite regularly nor uniformly, and which cut the surface into 

 little diamonds resembling shagreen. Colour dirty rusty white. Spire rather low, but 

 conical. Whorls of very rapid increase, apparently about 6. Suture linear, scarcely 

 impressed. Mouth very oblique, round, nacreous to the very edge. Outer lip very 

 slightly patulous, sharp on the edge, with a thick nacreous layer bevelled off to the edge 

 above and in front, but on the base turned over and advancing in a rounded pad beyond 

 the lip. Pillar lip consists of a rounded mass of nacre, backed and above obscured by a 

 considerable porcellanous deposit, which is widely but thinly spread out over the body, 

 so as to connect in a continuous sweep the outer and the pillar lips. It is distinctly 

 impressed with the scale-like pattern of the underlying sculpture. Its edge is abrupt and 

 chipped. Operculum thin, flat on the outside, highly porcellanous, with a translucent 

 and slightly thinner central area ; on the inside yellow, with many whorls, the nucleus 

 nearly central, the suture well marked, and the last whorl less disproportionately large 

 than usual. H. 0-87 in. B. 1*04, least 079. Penultimate whorl, "29. Mouth, height 

 075, breadth 0-65. 



The sculpture of this species is very peculiar. Iu form the shell is not unlike a Diloma, or 

 something between Litorina saxatilis and a Natica. In texture the shell is thinner than the 

 thickened lip suggests. The measurements of the mouth are not satisfactory, the outer edge of the 

 pillar-lip being indefinite ; if they be taken within the opening, they would give it as more truly 

 round. The apex is eroded ; and the whole aspect of the shell is so weathered that but for the 

 presence of the animal I should have taken it for an old and spoiled specimen. 



4. Turbo (Senectus) chrysostomus, Linne. 



Turbo chrysostomus, Linne, Syst. Nat, 12th ed., p. 1233, No. 614. 



Chemnitz, Conch. Cab., vol. v. p. 178, pi. clxxviii. fig. 1766. 

 ,, ,, Martyn, Univ. Conch., pi. xxvi. 



„ ,, Lamarck, Anim. s. vert., vol. vii. p. 41, and (ed. Desh.) vol. ix. p. 189, sp. 7. 



„ „ Dillwyn, Cat., vol. ii. p. 825, sp. 24. 



„ „ Deshayes, Encyclop. method, vers., vol. iii. p. 1093, sp. 5. 



Wood, Ind. Test. (ed. Hanley), p. 150, pi. xxx. fig. 23. 

 „ „ Eeeve, Conch. Icon. vol. iv. pi. vii. fig. 28. 



„ ,, Philippi in Conch. Cab. (ed. Kiister), p. 12, sp. 6, pi. iv. fig. 5. 



