REPORT ON MOLLUSCA 



87 



Trophon priestleyi, sp. nov. (Fig. 2) 



Shell small, very solid, narrowly fusiform. Whorls five, including a smooth 

 pointed protoconch of a whorl and a half, suture marked by a narrow groove. 

 Sculpture : there are two prominent keels on the periphery, another much smaller 

 just above the sutural groove, and another small one on the shoulder ; these reach 

 the outer edge of the lip. On the base of the last whorl are three more spirals, succes- 



FlG. 1 



Fig. 2 



sively diminishing anteriorly. These keels have thin, pinched, rather wavy edges, 

 and are separated by shallow furrows twice or thrice their breadth. Both keels and 

 interspaces are overridden by fine radiating threads. Aperture ovate, outer lip 

 bevelled within, inner lip slightly excavated. Canal short, broad, and slightly 

 recurved. Length, 5"5 ; breadth, 2 - 8 mm. 



One entire specimen and a few fragments. It is unusual in Trophon for the radial 

 sculpture to be subordinate to the spiral. Such forms as T. petter&i, Crosse, and 

 T. plebius, Hutton, form a passage to the present form. I presume that Siplw antarc- 

 tidis, Pelseneer,* is related to the species now introduced. 



* Pelseneer, Moll. " Belgica " Exped. 1903, p. 22, f. 60. 



