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



curved, sharp and patulous, but not quite appressed on the pillar, having there a minute 

 furrow behind it. H. 0'09 in. B. 0'042. Mouth, height 0*033, breadth 0"027. 



This species faintly recalls Rissoa striata, Adams, but is much more elongate. It is very slightly 

 like Rissoa aedonis, Wats., in sculpture, but not at all in form. 



E. Whorls flat and smooth (Cingula). 



31. Rissoa (Cingula) glabrata (v. Muhlfeldt). 



Helix glabrata, v. Muhlfeldt, Verhandl. BerL Gesellsch., 1824, voL i. p. 218, pL iii. fig. 10. 



Rissoa punetulum, Philippi, Enumeratio, vol. i. p. 154, pi. x. fig. 11, and (Rissoa glabrata) vol. ii. 



p. 130, sp. 32. 

 Cingula glabrata, Weinkauff, Conch. Mittelmeer., voL ii. p. 280. 

 Rissoa (Cingula) glabrata, Aradas and Benoit, Conch. Mar. Sicil, p. 208, No. 550. 



,, glabrata, Watson, Madeiran Rissose, Proc. Zool. Soc. Lond., 1873, p. 386, pi. xxxvi. fig. 24. 



„ (Nodulus) glabrata, Monterosato, Enumerazione, p. 26. 



February 10, 1873. Tenerife, Canaries. 70 fathoms. 

 Habitat. — Mediterranean (v. Muhlfeldt) ; Madeira (Watson). 



32. Rissoa [Cingula) rustica, 1 n. sp. (PI. XLIV. fig. 11). 



Station 122. September 10, 1873. Lat. 9° 5' S., long. 34° 30' W. Off Pernambuco. 

 350 fathoms. Red mud. 



Shell. — Strongish, ovate, conical, white, very obsoletely ribbed or ribless, blunt, 

 round tipped, with flat-sided whorls, a linear suture, a flatly conical base, an unvarixed 

 lip, and a moderate-sized mouth. Sculpture : Longitudinals — there are very slight lines 

 of growth, and sometimes extremely obsolete remote rounded ribs on the last whorl. 

 Spirals — there are vague traces of microscopic lines. Colour translucent white, with a 

 dull gloss. Spire conical, with almost perfectly continuous lines. Apex large and rounded ; 

 the extreme tip is barely visible in profile. Whorls 6, the last two barely convex, the 

 earlier ones quite flat on the sides ; the periphery is very obsoletely and roundly angu- 

 lated, the base short, conical, and barely convex. Suture linear, not impressed, very 

 little oblique. Mouth moderate, larger in the adolescent than in the full-grown shell, 

 oval, slightly pointed above and at the extremity of the pillar. Outer lip sharp, patulous, 

 but a little inverted above. Inner lip a very little spread out, but still defined on the 

 body ; on the pillar it is straight, sharp, and a little prominent, so as to leave a distinct 



1 Coarse. 



