370 THE VOYAGE OF H.M.S. CHALLENGEPw. 



tubercles, of which there are about 11 on the first ordinary and 16 on the last whorl ; on 

 the earlier whorls they are feebly prolonged downwards as riblets, but become weaker on 

 the last whorls. The whole surface is closely scratched with hair-like and somewhat 

 irregular lines of growth. Spirals — an exceedingly slight pad forms a faint inferior 

 margination to the suture : between this and the line of tubercles the profile is oblique 

 and straight, not concave : below the keel formed by the tubercles are a few very faint and 

 sparse spiral threads. Colour pale flinty, whence the name. Spire conical, with inter- 

 rupted profile-lines. Apex consists of two glossy, tumid, rounded whorls of nearly equal 

 size, and with a very slight suture. IVJwrls 8 in all, of slow and regular increase ; they 

 are shouldered above and almost cylindrical below the keel ; the last is small, contracts 

 from the keel, and has a short, conical, hardly tumid base prolonged into a short small 

 suout. Suture ■ very slightly impressed, rather oblique. Mouth small, narrow, pear- 

 shaped, angulated above, and drawn out into a short open canal in front. Outer lip 

 steeply curved above, a little flatly prolonged forward ; its edge, which retreats at the 

 canal, is prominently rounded in the middle, and forms a high shoulder above, between 

 which and the body is the rather deep, narrow, rounded sinus. Inner lip : there is a 

 thinnish glaze on the body and pillar, whose union is very slightly concave ; at that point 

 occurs the generic fold, which is somewhat remote within the mouth, and is a rather 

 strong thread; the front of the pillar is rather oblique, sharpish, and twisted. H. 0"41 in. 

 B. 0-15. Penultimate whorl, height 0'06. Mouth, height 0-09, breadth 0'07. 



This species differs from the preceding (which it very much resembles) in that the shell is 

 smaller, the whorls more sharply keeled (the carination, too, higher), the contraction of their lower 

 part less marked, the tubercles are rounder and tend less to be drawn out into riblets, the form of 

 the shell is narrower, and the apex is much smaller. 



4. Clionella, Gray, 1847. 

 Species. 



1. Clionella quadruplex, Wats. 4. Clionella amblia, "Wats. 



2. Clionella exsculpta, Wats. 5. Clionella wjlaophanes, Wats. 



3. Clionella tholoides, Wats. 6. Clionella lophoessa, Wats. 



1. Clionella quadruplex, Watson (PI. XIX. fig. 7). 



Pleurotoma {Clionella) quadruplex, Watson, Prelirn. Report, pt. 11, Journ. Linn. Soc. Lond., voL xvi. 



p. 253. 



Station 73. June 30, 1873. Lat. 38° 30' N., long. 31° 14' W. West of Azores. 

 1000 fathoms. Pteropod ooze. Bottom temperature 39 0, 4. 



Shell. — Very high and narrow, conical, scalar, ribbed, bluntly keeled, with a very 

 short conical base. Sculpture : Longitudinals — below the suture is a double collar of 



