596 



BEV. R. BOOG WATSON ON THE 



periphery, slightly arched across the base, nicked close to the 

 point of the pillar. Pillar-lip arched, strengthened by a thin 

 pad ; reverted on the umbilicus so as to leave a slight groove 

 behind it, with a slight tooth in front. From the body-whorl 

 it bends very much over to the left, so as largely to cover the 

 umbilicus, and then it curves over to the right to join the outer 

 lip on the base at an obtuse angle. Umbilicus small, oblique- 

 edged, funnel-shaped, nearly covered by the piJlar-lip, and con- 

 tracted within, scored with hair-like lines of growth. Height 

 0-255. B. 0-25, least breadth 2. Penultimate whorl 0*075. 

 Mouth, height 0-12, breadth O'll. 



This is a narrower shell than Basilissa alta, W., less ornamented 

 and with a smaller umbilicus. Than B. munda, W., this is a nar- 

 rower shell, the flexuous longitudinals are stronger, the supra- 

 sutural band is stronger, and in that species the infrasutural band 

 is wanting. 



3. Basilissa munda, W. (mundus.) 



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

 Palma, Canaries. 1125 fms. Fine volcanic sand. 1 young spe- 

 cimen. 



Shell. — Broadly conical, flat on the base, sharply angulated, small, 

 thin, delicate, smooth, glossy,* nacreous under a thin white calca- 

 reous surface. Sculpture. There are longitudinals, which are very 

 faint but still sharp, sinuated, showing the old lines of growth. 

 Of spiral^ there are over the whole surface very faint traces. At 

 the bottom of each whorl, about "01 in. above the suture, is a 

 sharp narrow thread, which on the last whorl is bordered below 

 by a second, rather higher and sharper, which forms the carina, 

 and which on the spire is buried by the overlap of the succeeding 

 whorl. On the base there are about eleven fine spirals, within 

 which is a strong furrow, and a projecting, crenulated, or rope- 

 like thread forming the edge o£ the umbilicus. Colour opales- 

 cent, from the underlying nacre shining through the polished, 

 thin, translucent calcareous layer of the surface. Spire high and 

 conical. Apex flattened, with the minute smooth embryonic 

 I5 whorl slightly projecting. Whorls 6, of regular and slow 

 increase (but the specimen is not full-grown) ; perfectly flat, 

 the slope being scarcely broken by the suprasutural thread. 

 Suture linear, almost invisible. Mouth perpendicular, irregu- 

 larly rectangular, broader than high. Outer lip sharp and thin, 

 with a slight open sinus ; sharply angled at the periphery, 



