... body - whorl occupying four - fifths of shell , contracting slowly to large fasciole . Suture undulating . Sculpture : 16 rather low axial ribs with wider interstices , on upper whorls reaching from suture to suture , but on body- whorl ...
... Body whorl with rounded angulation just above the suture , straight above this angulation . Body whorl with angulation corresponding to that of whorls of spire , straight above and convex below angulation . On penultimate whorl this ...
... whorls . The spire whorls are decorated in a similar fashion to the body - whorl . The varices , however , are less numerous on the upper whorls . This is the first time that this genus has been reported from the Eocene of the Pacific ...
... whorl , and has been slightly compressed laterally . The other four ... body chamber . The smaller septate whorls embrace each other about three ... body whorl is characterized by abrupt contraction and at the aperture embraces ...
... body whorl of large species as tightly coiled as preceding whorls , or more loosely coiled . Shoulder reduced on adult body whorl of large species . Protoconch con- sisting of about 3 naticoid whorls . Earliest sculptured whorls ...
... whorls . Nucleus of 11⁄2 whorls . Spire slightly turreted , about two - fifths the height of the aperture . Early whorls convex , later ones slightly angled half - way between the sutures and with a lightly concave shoulder . Body whorl ...
... whorls . Nucleus of 1 whorls . Spire slightly turreted , about two - fifths the height of the aperture . Early whorls convex , later ones slightly angled half - way between the sutures and with a lightly concave shoulder . Body whorl ...
... whorls five or six ; apex acute ; sutures impressed , the surface of each whorl just below the suture being slightly concave , giving it a collar - like effect . Sides of whorls convex ; body whorl rather ventricose , about two - thirds ...
... body - whorl of a Platyceras of the type of P. bisulcatum ( Hall ) . It is apparently new , but with such meagre materials I do not venture to describe it . The body - whorl is free , and the apex has evidently been small , and has ...
... body whorl , inclu- ding the anterior two - thirds of the mouth and , on the opposite side , the sur- face , almost to the suture . It resembles somewhat V. mutabilis Con . , but the body whorl is more convex in the middle , although ...