492 GASTROPODA. [Pectinibranchia. 



Hob. Sandy bays between the North Head and Takapuna, type 

 (T. F. Cheeseman) ; Te Onepoto, near Lyttelton (H. S.) ; Chatham 

 Islands ; Kermadec Islands (Captain Bollons) ; Bay of Islands. 



Remark. As Mr. E. A. Smith's species was never figured, I give 

 preference to Hutton's name. 



Fossil in the Pliocene. 



3. Bathytoma engonia, Watson, 1881. Plate 21, fig. 17. 



Pleurotoma (Genota) engonia, Wats., J.L.S., xv, 1881, 405 ; Chall. Rep., 

 xv, 300, pi. 20, f. 7. P. engonia, Wats. : Button, P.L.S. N.S.W., x, 115. 

 Genofia engonia, Wats., Index, 70. 



Shell fusiform, biconical, with an expressed rounded keel angulat- 

 ing the whorls, and a broad prominent lopsided beak. Sculpture : 

 There are no axial ribs ; the lines of growth are strong, hair-like, 

 unequal, and close-set, on the keel they are exceptionally strong, 

 regular, and a little remote, as they are also at the top of the whorls 

 in the suture. The whorls aTe angulated about the middle, projecting 

 in a rather narrow, prominent, rounded keel, almost crenulated by 

 growth-lines. The whole surface covered by small, broadish, rounded, 

 close-set spiral threads, somewhat granulated at the base. On the 

 left side of the point of the beak and also on the earlier regular whorls 

 they tend to become obsolete. Colour porcellanous - white. Epi- 

 dermis thin, yellowish, membranaceous. Spire high, conical, about 

 the same height as the aperture. Protoconch blunt, rounded, of 2 

 smooth globular whorls. Whorls 8, broad, short, regularly increasing, 

 the last rather large, with a sloping slightly concave shoulder, straight 

 below the keel ; at the top of each whorl there is a slight collar, which 

 gives the effect of a slight canaliculation to the suture ; base somewhat 

 swollen, prolonged into a short broad unequal-sided beak. Suture 

 strong and slightly canaliculated. Aperture large, almost rhomboidally 

 pear-shaped, sharply angled above, and with a broad open canal 

 below. Outer lip regularly curved, thin and sharp, with an open 

 V-shaped sinus at the shoulder, rounded at the angle ; below this it 

 sweeps downwards and a little forwards, forming a very low-shouldered 

 wing ; towards the lower part of the aperture it curves very regularly 

 backwards to the point of the pillar. Columella narrow and short, 

 very obliquely truncate below, with a fine, but strong, sharpish twisted 

 edge. Inner lip polished and porcellanous, rather broadly excavated 

 in the substance of the shell ; scarcely convex on the parietal wall, 

 very slightly concave at the junction with the columella. (Watson.) 



Diameter, 13 mm. ; height, 31-9 mm. 



Animal unknown. 



Type in the British Museum. 



Hab.OS East Cape, in 700 fathoms ; '" Challenger " Station 169. 

 Also off Inosima, Japan, in 345 fathoms. 



Remark, Watson remarks that this species has a most striking 

 resemblance with the fossil Pleurotoma cataphracta, Brocchi. This, 

 however, is the type of the genus Bathytoma. 



