MOLLTJSCA OF THE ' CHALLENGER ' EXPEDITION. 263 



This Paludina-like form resembles no JVatica known to me. It is 

 narrower, longer in the last whorl, and higher in the spire than the 

 most exceptional forms of JST. affinis, Gm., var. clausa, Brod. & Sow. 

 Philippi, in Krister's Mart. & Chem., reproduces pi. vii. l,JSf. linibata, 

 d'Orb., Patagonia, and pi. vii. 2, N. isabelliana, d'Orb.,frorn South 

 America, which vaguely have somewhat of the same features, and 

 his iV*. tenuis, pi. xiv. 3, has so too ; but these are species I do 

 not remember to have seen, and none of the descriptions apply. 



9. Natica prasina, n. sp. 



St. 149 d. Jan. 19, 1874. Lat. 49° 32' S., long. 70° E. Balfour 

 Bay, Royal Sound, Kerguelen. 60 fms. Mud. 



St. 149 e. Jan. 20, 1874. Lat. 49° 28' S., long. 70° 13' E. 

 Royal Sound, Kerguelen. 28 fms. Mud. 



Shell. — Conically globose, rather high in the spire, with umbilicus 

 closed, thin, with a pale green roughish epidermis. Sculpture. 

 Longitudinals — there are on the lines of growth slight puckerings 

 of the fibrous epidermis. Spirals — there are some slight, open, 

 irregular, and unequal furrowings of the surface, with microscopic 

 scratchings. Colour : a pale buff colour below the dull greenish epi- 

 dermis, which is fibrous, thin, easily rubbed through, but persistent. 

 Spire more or less high, the whorls rising very considerably above 

 each other in high rounded steps. Apex extremely large for the 

 size of the shell but not prominent, being rounded, with the extreme 

 tip sunk in and generally eroded. Whorls 5, of which about 1 J are 

 embryonic ; they are globose, and increase regularly and slowly. 

 Suture deep, very slightly channelled, straight, but towards the 

 end a little oblique, llouth large, open, circularly oval, little 

 oblique, right-angled above, fully rounded below, with a scarcely 

 perceptible angulation towards the point of the pillar, slightly 

 flattened on the inner lip ; its height is nearly seven ninths of the 

 whole height. Outer lip — leaving the body-whorl at a right angle, 

 it sweeps round very fully and regularly to the pillar ; it is thin. 

 Inner lip a little hollowed, with, on the body, a very slight pro- 

 jection ; there is scarcely any pad at the upper corner of the 

 mouth, and the callus is very thin on the body ; above and at the 

 umbilicus it is thinly and somewhat broadly reverted, so as 

 quite to conceal the opening or to leave at most a mere chink ; 

 at the pillar it narrows, and there is at this point a slight trans- 

 verse angulation ; the pillar is the only part of the lip which is at 

 all thickened, and that but slightly ; the edge is rounded and 



