120 REV. R. BOOG WATSON ON THE 



the pillar, the scar of the siphonal cut. Besides the larger sys- 

 tems of sculpture, there are some faint and irregular traces of 

 microscopic rounded longitudinals and sharper spirals. Colour 

 translucent white. Spire high, narrow, with very straight out- 

 lines, and scarcely contracted. Apex excessively blunt and 

 abrupt, the extreme point being rounded and barely rising into 

 view ; it is quite smooth and polished. The second whorl is 

 longitudinally ribbed and polished; on the third the ordinary 

 sculpture begins. Whorls 11, convex, constricted suddenly 

 below and gradually above. Suture excessively minute and faint 

 in itself, but its place strongly marked by the constriction of the 

 whorls above and below. Mouth very small, oval, perpendicular, 

 pointed above, and with a large open rounded slit in front, whose 

 edge is hardly reverted. Outer lip thin, advancing on the base 

 much beyond the point of the pillar. Inner lip a thin glaze, 

 with microscopic corrugations on the pillar. Pillar very short, 

 with a broad base spreading out to meet the outer lip, straight, 

 with a broad but sharp point. H. 023. B. 0*05. Penultimate 

 whorl, height O03. Mouth, length 0-028, breadth 002. 



This species in general aspect is very like Cerithiopsis metaxa, 

 della Chiaje, but differs in not having the sharp sculptured apex ; 

 the whorls, in consequence of the sutural contraction, are more 

 rounded ; the longitudinals are swellings of the whole shell, not, 

 as in that other, mere projecting tubercles ; the spirals are more 

 definitely continuous ; the longitudinal rows of tubercles run 

 less definitely from whorl to whorl, and have a strong sinistral 

 twist as they proceed down the spire, while in C. metaxa their 

 continuous lines are very straight. 



20. Cerithiitm (Bittitjm) delicatum, n. sp. 



St. 135. Oct. 18, 1873. Nightingale Island. Tristao da 

 Cunha Islands. 100-150 fms. 



Shell. — Small, narrow, conical, blunt, with slightly convex out- 

 lines, rather tumid on the base, ribbed, but not reticulated, thin, 

 translucent, glossy, white. Sculpture. Longitudinals — there are 

 on each whorl about 17 narrow, straight, rather tumid ribs, 

 parted by furrows of about the same breadth. These ribs run 

 straight down the spire, but are on the body-whorl slightly ob- 

 lique. This whole system of ribs and furrows ceases abruptly at 

 the edge of the base through a levelling up of the surface. There 

 are many microscopic rounded lines, which are most distinct in 

 the furrows, but especially on the base. Spirals — there are faint 



