416 GASTROPODA. [Pectinibranchia. 



pillar, well limited, spreading over the concave parietal wall, narrowed 

 below to a fine ridge on reaching the canal. An umbilical narrow 

 chink is sometimes present. Operculum with a terminal nucleus. 



Diameter, 13 mm. ; height, 26 mm. (typical form). Diameter. 

 15mm. ; height, 31 mm. (elongated form). 



Dentition unknown. 



Type. Collection of J. de Conch., Paris. 



Hob. North and .South Islands, but not common, between tide- 

 marks to about 20 fathoms : Chatham Islands. Also Australia and 

 Tasmania. 



Remarks. This species is very variable, according to its habitat. 

 The short and solid form is living on rocks at low water ; the thin 

 and slender shell inhabits mud-flats ; and T. squamosissima is an ex- 

 treme form from deep water. (C. Hedley.) 



13. Trophon plebejus, Button, 1873. Plate 46, fig. 19. 



Fusus plebeius, Hutt., C.M.M., 9. Trophon plebeius, Hutt., J. de Conch., 

 1878, 12; Man. Conch. (1), ii, 145; Plioc. M., 39, pi. 6, f. (>. Kalydon 

 plebeius, Hutt., T.N.Z.I., xvi, 220. Urosalpinx plebeius, Hutt. : Coss- 

 mann, Ess. Pal. Comp., v, 50. Trophon incisus, Gould : Hut ton. 

 M.N.Z.M., 48 ; not of Gould. 



Shell small, fusiform, solid, with reticulated sculpture, cinereous 

 to dark brown. Sculpture consisting of narrow rounded or sharp axial 

 costa>, about 18 on a whorl, reticulated by spiral lira ; usually 3, but 

 occasionally as many as 5, on the spire-whorls : points of intersection 

 slightly nodulous ; fasciole distinct. Colour dark brown, sometimes 

 with a white spiral band below the shoulder ; inside of aperture 

 brownish-purple, sometimes whitish with brown bands ; inner lip 

 light brown. Spire conic, of about the same height as the aperture 

 with canal. Protoconch small, of 1 smooth and convex whorls, the 

 nucleus minute, globular. Whorls 6, the last high, shouldered, more 

 or less distinctly angled ; base contracted above the canal. Suture 

 superficial. Aperture subvertical, oval, angled above, with a short 

 open canal below, which is bent to the left and somewhat recurved. 

 Outer lip with an angle above, crenulated by the spiral sculpture, 

 sharp, grooved or toothed inside. Columella vertical, straight. Inner 

 lip narrow, limited by a fine groove, extending as a thin layer over the 

 lightly excavated parietal wall, narrowed below towards the canal. 

 A very small umbilical fissure is sometimes present. Opercnlwn with 

 a subapical nucleus. 



Diameter, 10mm.; height. 20mm. (type). Diameter, 8mm.; 

 height, 16 mm. (usual size). 



Dentition not known. 



Type in the Dominion Museum, Wellington. 



Hab. Throughout New Zealand, between tide-marks and in the 

 laminarian zone, common ; Kermadec Islands. 



fossil in the Pliocene. 



