RECENT AND TERTIARY SPECIES OF LEDA AND NUCULA. 179 
ing rapidly, and bearing a row of pointed crenate lamellar 
tubercles or spines on the angle, above which is a continuous 
plain revolving ridge ; last whorl about two-thirds of the 
length of the shell ; spire elevated, acuminate ; aperture 
elongate, with two sinuses, one corresponding to the angle 
of the whorls, and the other to the ridge above it ; canal 
long, columella smooth. From the angle of the last whorl 
to the end of the canal is about one half the length of the 
shell. Length 13 mill., extreme breadth 5 mill. 
Though, on account of the keel above the angle of the 
whorls and the corresponding sinus of the aperttire, I have 
provisionally described this little shell as a Pleurotoma j and 
assign it as an ally to PI. rotata (Miocene Europe), I cannot 
overlook its likeness to • Fusiis pagodus and F. echinatus. It 
also has a striking similarity in general outline to the 
Thatcheria mirabilis of G. F. Angas (P.Z.S; 1877, p. 529, 
pi. liv. , f. 1), which is not, indeed, so ornate as our species, 
and is much larger. 
Miocene, Jamaica (H. Vendryes).- 
5. Purpura trinitatensis, Guppy (PI. vii. , f. 17). 
Proc. Scient. Assoc. Trinidad, 1869, p. 366. 
Ann. and Mag. Nat. Hist., Jan. 1875, p. 50. 
Explanation of Plate YII. 
Fig. 1 . Leda egregia, exterior of left valve. 
„ 2. „ „ another specimen, interior. 
„ 3. Nucula crosbyana, left valve, exterior ; 3 a, interior. 
„ 4. Leda clara, left valve, interior. 
,, 5. „ illecta, right valve, exterior. 
6. „ vitrea, right valve, interior ; magnified. 
„ 7. „ bisulhata, left valve, exterior ; magnified. 
„ 8. „ acuta, right valve, exterior ; magnified. 
„ 9. „ packeri , right valve, exterior. 
