DUNBBY GASTEROPODA.. 45 



PLEUEOTOMAEIA OBCOMCA, n. sp. PI. 3, fig. 6. 

 Height 29 mm, Greatest breadth, 30 mm. 



Shell conical ; apex obtuse ; the newer whorls not increasing 

 at the same rate as the apical ones : the outline is curved, and 

 the cone of blunted form. 



"Whorls seven, obtusely angular; the part above the sinus- 

 band becomes almost concave in the old whorls ; the part below 

 is inclined to be squarely-rounded ; the surface is marked with 

 oblique transverse lines above, and transverse lines as well as 

 longitudinal lines below — the latter being the stronger ; on the 

 apical whorls the transverse lines are so strong that they 

 constitute costae. 



The umbilicus is open ; the base of last whorl is very slightly 

 conical ; lines radiate from the umbilicus outward. Sinus-band 

 elevated. 



I first was disposed to consider this a less depressed form of 

 P. sulcata, as the ornamentation is jprecisely the same, but the 

 sinus-band is in a depression in that species, and here it is 

 elevated ; moreover, we have no transition between the two forms ; 

 one is a more obtuse cone, and the difi'erence seems constant. 



There are two specimens in the Museum. 



Locality — Dundry. Inf. Ool. 



PLEUEOTOMAEIA DISTINGrENDA, n. sp. PI. 3, fig. 2. 



Height 18 mm. Breadth 19 mm. Angle of spire 70*^. 



Shell conical, regular ; whorls straight- sided, ornamented with 

 rows of separate tubercles, placed obliquely in opposite directions 

 on either side of the sinus-band. Above the band are three rows 

 of compressed tubercles ; below it are three of smaller round 

 tubercles, and then three to four of larger ones (the distinction is 

 not well seen in our plate) which form the angle in the last 

 whorl ; sinus-band with a central salient ridge, and crossed by 



