i6i 



THE 



JOURNAL OF CONCHOLOGY. 



Vol. II. APRIL, 1905. No. 6. 



ROSTELLARIA DELICATULA^ Nevill. 

 Notes upon its distribution and limits of variation. 



By tames COSMO MELVILL and ROBERT STANDEN. 



(Read before the Society,. May ii, 1904). 



Plate II. 



This particularly attractive Gastropod, always inhabiting abyssal 

 dep'hs, was described in 1881,^ by the late Mr. Geoffrey Nevill, but 

 not figured ; his account of it being here transcribed as follows : — 



Rostellaria delicatula n. sp. 



" Distinguished at once from all the other living species of the 

 genus by its thin, delicate, and translucent substance, in these respects 

 showing a highly important approach to some fossil forms. Colour a 

 pale ochraceous brown, lineated on the last whorl with four narrow 

 white bands, each of which terminates in one of the four projecting 

 digitate processes of the outer lip, one only of these bands appearing 

 in the middle of the preceding four whorls ; spire not quite half the 

 entire length, apex moderately acute; whorls loj, moderately con- 

 vex, the last conspicuously tumid and like the preceding one, marked 

 with a shght sutural depression, produced at the base into a short 

 canaliculation, relatively less developed than in any of the otiier 

 known species, this " canal " is slightly tortuously deflected, more 

 conspicuously so than in R. tnagmcs Chemnitz ; the first three or 

 four whorls are sculptureless, the next three or four inconspicuously 



I Nevill, Journ. Asiat. Soc. Bengal, vol. 50, pt. 2, p. 262, 1881. 



