436 THE VOYAGE OF H.M.S. CHALLENGER. 



pi. xi. fig. 3 belongs-, is Natica variabilis, Reel, the type of which, figured by Reeve, is in the 

 British Museum. Adams' Natica marmorata is also the same species, for he says that McAndrew 

 dredged it at the Canaries, and his description and figure agree perfectly with the Natica variabilis, 

 Recluz, found there. H. Adams' name of Natica marmorata has indeed been associated with a 

 Philippine Island species, and in the McAndrew Collection, British Museum, this name is attached to 

 a specimen derived {teste McAndrew's own hand) from the Red Sea, but that species, though extremely 

 like, is, I think, distinct (see Natica pseustes, Wats., at p. 445). 



The Messrs Adams (Genera, vol. i. p. 207) put Natica variabilis into their group Lunatia, 

 which they ascribe to Lamarck, but which was really proposed by Gray in his List of Genera, 

 p. 149, 1847; for some reason, however, he does not reproduce it in his Guide, 1857. The present 

 species does not belong to that group, for its umbilicus is not "wide" nor " pervious," and is 

 " funiculate," and the operculum is not " simple, cartilaginous," but is calcareous, with a border on 

 the right of three narrow flat raised ribs (of which the exterior one is often split into two), parted by 

 very narrow shallow sharp-cut furrows. Parallel to these six or eight flat elongated tubercles score 

 the left edge of the opei-culum towards its apex. 



Dr Gwyn Jeffreys (loc. cit.) says that Natica prietoi, figured by Hidalgo (Mol. Mar. de Espana, 

 pi. xx.b. figs. 2, 3), is this species, " ex typo." I have not seen Dr Hidalgo's type, but should not, 

 from the figure, have taken it for Recluz's species. 



8. Natica radiata, Watson (PI. XXVII. fig. 5). 



Natica radiata, Watson, Prelim. Report, pt. 7, Joum. Linn. Soc. Lond., vol. xv. p. 258. 



North Atlantic, April or May 1873. Over 1000 fathoms. 



Station 33. April 4, 1873. Lat. 32° 21' 30" N., long. 64° 35' 55" W. Bermuda. 

 435 fathoms. Coral-mud. 



Shell. — Strong, conically globose, with a high scalar spire, laterally compressed, so that 

 its outline is peculiarly square ; mouth small ; umbilicus open, deep, and funiculate. 

 Sculpture: Longitudinals — there are many unequal but generally fine lines of growth, 

 which are strong above, and there radiate like curved spokes from the suture ; they are 

 sharpest and highest on the earlier whorls ; on the base they are again stronger, and on 

 the edge of the umbilicus they are sharply bent back, and form there an indistinct carina. 

 Spirals — the whole surface is covered with very faint and narrow obsolete lines and furrows, 

 over which is a minute system of sharp microscopic scratches. Colour polished porcel- 

 lanous white, with an indistinct and indefinite staining of buff below the shoulder and 

 round the outside of the umbilicus. Epidermis : within the umbilicus are remains of a 

 rather strong, thinnish, smooth, but puckered, blackish-yellow membrane. Spire high, 

 scalar. Apex large, tumid, but with the extreme tip a very little bent down. Whorls 5, 

 of which If are embryonic and glossy, rounded and rising high, each above the preceding 

 one ; they are laterally compressed so as to give a peculiar character to the shell, which is 

 angulately shouldered below the suture, and tumid aud broad at the base. Suture oblique, 



