.348 THE VOYAGE OF H.M.S. CHALLENGER.^ 



more threads of variable strength. Colour porcellanous white. Spire high, narrow, coni- 

 cal, subscalar. Apex a little bluntly conical, consisting of 4 to 5 whorls, of which the 

 upper ones are small and smooth ; the last two are ornamented with minute ribs or elon- 

 gated bosses. Whorls about 10 in all, high and narrow, of very slow and regular increase, 

 slightly convex, with a sloping shoulder, rather cylindrical in the middle, and slightly con- 

 tracted below ; the last whorl is small, very slightly tumid, with a very contracted base 

 and a small subcyliudrical snout, the point of which is slightly reverted and nicked. 

 Suture very minute and concealed, in spite of the contractions of the whorls and the 

 inferior margination. Mouth short, small, and pear-shaped, not narrow, triangularly 

 pointed above, and ending below in the short, rather open canal. Outer lip a pretty 

 regular curve ; its edge is prominent below with a low shoulder above, leaving a wide 

 funnel-shaped opening for the rather shallow rounded sinus. Intier lip very narrow, thin, 

 and short, dying out early on the narrow twisted oblique edge of the pillar, which is 

 slightly reverted along the side of the canal so as to produce a small twisted furrow. The 

 line of junction of the pillar and the body is very concave. H. - 32 in. B. (HI. Pen- 

 ultimate whorl, height 0"07. Mouth, height (H2, breadth O'OG. 



The specimen of this species from Station 5tj has the spiral threads very much finer than that 

 from Station 24. The species has a strong superficial likeness to Plcurotoma emcndata, Monterosato 

 = Plcurotoma rcnieri, Phil., nee Scac. ; but that is a broader and larger shell, has a more tumid 

 body-whorl and a longer base ; its whorls are not so high-shouldered, are more convex, are not so 

 strongly keeled, are not so deeply and strongly parted by the square impressed suture ; and the apex 

 is of the large blunt dome type, consists of only two whorls, and is simply carinated. 



2. Clathurella, Carpenter, 1856. 



Millet's earlier name (1820) of Dcfrancia, which has been largely adopted, is preoccupied by 

 Bronn (1825) for a genus of Polyzoa, which had indeed previously been named Pelagia by Lamouroux 

 (1821), but that name having been preoccupied by Pt'ron in 1809 for a genus of the Acalephas, the 

 Dcfrancia of Bronn must come into use. The Dcfrancia of Millet must, therefore, unfortunately be 

 dropped, and Carpenter's name, Clathurella, adopted. 



Species. 



1. Clathurella crispata, Jan. 11. Clathurella circumvoluta, Wats. 



2. Clathurella formosa, J effr.j 12. Clathurella chyta, Wats. 



3. Clathurella leufroyi, Mich. 13. Clathurella perpauxilla, Wats. 



4. Clathurella reticulata, Renier. 14. Clathurella perparva, Wats. 



5. Clathurella hormophora, Wats. 15. Clathurella kala, n. sp. 



6. Clathurella chariessa, Wats. 16. Clathurella homoeotata, n. sp. 



7. Clathurella pachia, Wats. 17. Clathurella pmxellana, n. sp. 



8. Clathurella pudens, Wats. 18. Clathurella phyxanor, n. sp. 



9. Clathurella araneosa, Wats. 19. Clathurella (Daphnella ?) monoceros, Wats. 

 10. Clathurella streptophora, Wats. 20. Clathurella (Daphnella) compsa, Wats. 



21. Clathurella (Daphnella) aulacoessa, Wats. 



