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



I know nothing with which to compare this remarkable species. Clavatula albicans, Hinds, 

 '' Sulphur," p. 23, No. 84, pi. vii. fig. 8, has somewhat of its general features ; but there resemblance 

 ends. Trochus {Margarita) nitens, Jeffr., has a somewhat similarly ornamented suture; as has also 

 Cithna margaritifera (Wats.). 



6. Clathurella chariessa 1 (Watson), (PI. XX. fig. 6). 



Pleurotoma {Dcfrancia) chariessa, Watson, Prelim. Report, pt. 10, Journ. Linn. Soc. Lond., vol. xv. 



p. 458. 



Station 24. March 25, 1874. Lat. 18° 38' 30" N., long. 65° 5' 30" W. North of 

 Culebra Island, West Indies. 390 fathoms. Pteropod ooze. 



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. 



Station 78. July 10, 1873. Lat. 37° 26' N., long. 25° 13' W. San Miguel, Azores. 

 1000 fathoms. Volcanic mud. 



Station 85. July 19, 1873. Lat. 28° 42' N., long. 18° 6' W. Off Palma, Canaries. 

 1125 fathoms. Volcanic mud. 



Station 122. September 10, 1873. Lat. 9° 5' S., long. 34° 50' W. Off Pernambuco. 

 350 fathoms. Eed mud. 



Shell. — High, biconical, a little tumid, carinated, white, thin, faintly, shortly, and 

 obliquely ribbed, with a high, subscalar, small-pointed spire, and a slightly tumid little- 

 contracted base, produced into a long narrow snout. Sculpture: Longitudinals — there 

 are on the last whorl about 20 short oblique folds, which die out almost immediately ; 

 they are highest at their origin below the sinus-area, and are parted by flat intervals 

 somewhat broader than they ; they diminish in number up the spire, and do not reach 

 the lower suture : there are further obsolete lines of growth, which in the sinus-area are 

 strong, and at the suture form sharp little folds parted by wide unequal intervals. 

 Spirals — the sutural area is wide, but scarcely concave ; it is bordered by the blunt 

 angulation forming the- keel, which is greatly strengthened by the prominence of the 

 origin of the longitudinal ribs. From the keel downwards the shell is 

 covered by superficial, flattened, irregular, and unequal threads parted by 

 narrower shallow furrows ; these become slightly stronger and more regular 

 on the snout. Colour ivory-white ; the apex is ruddy brown. Spire coni- 

 cal, high, rather narrow, subscalar, sometimes scalar from the squareness 

 with which the sinus-area stands out in the upper whorls. The lines of 

 profile are very much interrupted by the prominence of the keel. Apex small, ruddy 

 brown, consisting of 4^ conical whorls ; of these the lower two-thirds is covered with 

 very minute reticulations, while the upper part is scored with minute curved bars, the 

 surface between which is very slightly spirally marked; it ends in a minute tip a 



1 x a °' u " graceful. 



