536 Br. H. Woodward — On Fossil Shells from Sumatra. 



Shell fusiform, costellated, transversely striated, whorls 8-9 in 

 number, somewhat angular, tabulated above, smooth ; costa? thick, 

 prominent at the angles, truncated above ; suture marginatecl ; aper- 

 ture scarcely equal to half the length ; canal straight ; columella 

 smooth ; lip thickened, expanded, striated within, sinus deep, rounded. 



After instituting a careful comparison between this Sumatran 

 fossil and a series of very similar forms from the Miocene faluns of 

 Touraine, Dax, and Bordeaux, obtained by M. Deshayes for the British 

 Museum, and figured and described by MM. Basterot, and Des 

 Moulins, I have arrived at the conclusion that this Pleurotoma, PI. 

 XIV. Fig. 2a, b, is identical with the Pleurotoma terebra, Bast., 

 and that PL multinoda, Des Moulins, and PL Dufourii, Des Moul., 

 must also be considered as synonymous with it, and with the 

 Sumatran species ; the variations which they present being only 

 individual, and too trivial to be treated as of specific value. 



I have further compared this Sumatran fossil with the PL (Clava- 

 tula) sinensis of Hinds, — a recent shell found living at New Guinea, 

 the Straits of Macassar, Celebes, in the China Seas, and at Malacca; — 

 and in doing this I have had the benefit of the opinion of my colleague 

 Mr. Edgar A. Smith, of the Zoological Department. The chief differ- 

 ences appear to be in the form and proportion of the last whorl to 

 the entire length of the shell, the last whorl being smaller and 

 shorter in the recent shell, than in the fossil. In the Sumatran fossil 

 it is less contracted and attenuated towards the base, and occupies 

 nearly half the entire length, but in PL sinensis it is much shorter 

 in proportion. In the latter, the upper part of the volutions is more 

 concave beneath the wavy keel, or ridge, which borders their margin, 

 and the costaa or plica? are more prominent and slightly more angular. 

 The spiral or transverse sculpture offers but little difference in the 

 two species. 



In all the larger specimens of this form from Bordeaux (especially 

 in PL terebra, and PI. multinoda) the aperture is always consider- 

 ably less than half the entire length of the shell ; but in the smaller 

 French specimens the proportions are nearly the same as that of 

 the smaller Sumatran one. The spire of the smaller specimens is 

 also more acute. 



The following are the relative dimensions of the species of Pleuro- 

 tomce referred to : — 



Species of Pleurotoma proposed to be 

 placed together. 



Pleurotoma terebra, Bast. Sumatra 



,, Bordeaux 



■ multinoda, Lamk. Sau- 

 brigues. Dax 



Dufouri, Des Moul. Dax. 



■ sinensis, Hinds (recent) .., 



Large Specimen. 



o ?> 



■3 S 



bc"S 



12 

 10 



11 



9 



Hi 



30 

 26 



30 



22 



10 

 8 



10 



7 



Small Specimen. 



•S3 

 8 8. 



a 



16 



19 



17 

 17 

 17 



