REPORT ON THE GASTEROPODA. 609 



This species most resembles Bissoa marionensis, Wats. The differences are not easily made 

 obvious in words, but the whole style of the shell is different ; the form of mouth, of the last whorl, 

 and of apex is diverse, more than the measurements would seem to indicate. I have parted them with 

 very considerable hesitation, but I believe them to be distinct. From Eatowklla kerguelensis, E. A. 

 Smith, this species differs in colour, texture, and form of operculum, which is that of a typical Eissoa. 

 The radula is also that of the genus, only the centre tooth is a little more cusped and serrated, while 

 the uncini, especially the outer one on either side, are less so than Troschel's figures suggest for the 

 genus. 



41. Eissoa (Setia) philomelce, 1 n. sp. (PI. XLV. fig. 2). 



Station 135c. October 17, 1873. Lat. 37° 25' 30" S., long. 12° 28' 30" W. Oft' 

 Nightingale Island, Tristan da Cunba. 100 to 150 fatboms. 



Shell. — Thin, ovate, conical, subbyaline white, glossy, with a blunt rounded top, 

 convex wborls, a slightly impressed suture, a rounded base, an unvarixed lip, and an oval 

 mouth. Sculpture : none, but slight lines of growth. Colour subbyaline white, with a 

 somewhat glossy but not brilliant surface. Spire conical. Apex bluntly rounded. 

 Whorls barely 5 ; on the sides they are convexly conical : the last two are of somewhat 

 rapid increase. Suture slightly impressed, almost horizontal. Mouth rather large, oval, 

 barely pointed above. Outer lip sharp, direct above, but a little patulous in front. Inner 

 lip : on the body thin, but defined ; at the pillar slightly reverted, with a small furrow 

 and minute umbilical chink behind it. H. 0'058 in. B. 0"033. Moutb, height 0'027, 

 breadth 0'022. 



This species very much resembles Eatoniella suirufescens, E. A. Smith, but the spire is narrower, 

 and is not truncated, as in that species, by the sudden abrupt termination of the apex ; the texture 

 of the shell, too, is much more delicate. 



42. Rissoa (Setia) quisquiliarum, 2 n. sp. (PI. XLV. fig. 3). 



Station 75. July 2, 1873. Lat. 38° 38' N., long. 28° 28' 30" W. Off Fayal, Azores. 

 450 to 500 fathoms. Volcanic mud. 



Shell. — Stout, suboblong, conical, with a blunt rounded tip, very slightly convex 

 whorls, faintly impressed suture, a rounded base, a varixed lip, and an oval -mouth. 

 Sculpture : none, except very faint lines of growth, a broadish labral varix, and a few (five 

 or six) obsolete spirals on the base. Spire rather narrow, conical. Apex bluntly rounded. 



1 So called from the island. 



2 I have no intention of stigmatising the species as worthless, but only that the solitary representative I 

 know of it was picked at the last moment out of refuse. 



(ZOOL. CHALL. EXP. — PART XLIL — 1886.) Xt 77 



