Br. H. Woodward — On Fossil Shells from Sumatra. 545 



retaining its colour and ornamentation, which consists of concen- 

 trically arranged, somewhat elongated white spots upon an olive- 

 brown ground. 



The painting of this shell calls to mind that of N piinetulata, 

 Lamarck, a living West-Indian species, but the form and columellar 

 region are different. This shell might also be compared with the Nerita 

 Bumphii of Martin (see Die Tertiarschichten auf Java, t. xiii. fig. 19). 



Dimensions : — Height 7 mm. ; breadth 14 mm. 



Formation : — (Subfossil ? ') Tertiary. 



Locality : — Government of the West Coast of Sumatra. 



76. Neritopsis Morrisianus, H. Woodw. PI. XV. Fig. 7, a, b. 



Shell subglobose, neritoid, thick, spire very short and small, sur- 

 face ornamented with numerous linear tuberculated lirse of nearly 

 equal size, 15 to 16 in number, the tubercles being united to those in 

 the rows above and below them by delicate oblique striae ; aperture 

 subovate, inner margin of outer lip distinctly denticulate ; columellar 

 margin deeply notched. 



Dimensions : — Height 11 mm. ; breadth 11 mm. 



M. Grateloup, in 1832, established the genus Neritopsis, for a 

 fossil shell from the Miocene of Dax, Landes ; which he named 

 N. moniliformis (Actes de la Societe Linneenne de Bordeaux (tome 

 v. no. 27, p. 125, pi. 3, fig. 1, 2). This species is four times as 

 large as our Sumatran shell, and agrees better with the living N. 

 radula, Linn., found in the seas around the Sandwich Islands. 2 

 From both of these it may, however, be distinguished by its shorter 

 spire, the smaller number of the granular ridges and the coarser lirae 

 within the labrum. The abrupt notch in the columella is of pre- 

 cisely the same form as in the recent species. 



The operculum of the latter is a comparatively recent discovery. 

 It is of a thick shelly substance, and has a prominence upon the inner 

 side, which fits into the notch in the columella. It is described by 

 M. Souverbie (Journ. de Conchyliologie, 1874, vol. xxii. p. 199), 

 and in the succeeding volume of the same work by M. Crosse. The 

 curious fossil organisms from the Upper Lias of Normandy (Soane- 

 et-Loire and Calvados), from Wiirttemberg, and from the Coral-Rag 

 of England, upon which MM. Eudes and Eugene Deslongchamps 

 founded their genus Peltarion in 1859, are only the opercula of a 

 species of Neritopsis? The operculum of Neritopsis has also been 

 named Scaphanidia by J. Miiller. Mr. Ealph Tate observes 4 of the 

 genus Peltarion, that it is " Founded on the mandibular armature of 

 Tetr abranchiate Cephalopods." 



1 The fresh condition and coloration of this shell render it difficult, in the absence 

 of more exact knowledge of these beds, to refer it to any but a very modern deposit. 



2 Twenty fossil species of Neritopsis are described from the Trias ?, Lias, and 

 Oolites. Dr. Homes has also figured a Neritopsis (which he refers to the recent 

 N. radula) from the Vienna Basin. I find that Homes considers Grateloup's N. 

 monilifera to be only a synonym of N. radula (Foss. Moll, des Wiener Beckens, 

 p. 528, pi. 47, fig. 8). 



3 See Jules Beaudouin (Bull. Soc. Geol. France, 2e serie, t. xxvi. 1869, p. 182). 



4 Manual of Mollusca, by Dr. S. P. "Woodward, Appendix by Ralph Tate, 1875, 

 pp. *12 and *13, fig. 11. 



DECADE II. — VOL. VI. — NO. XII. 35 



