Triphot-a.} GASTROPODA. 255 



tubular, short., basal canal. Outer lip sinuate near the suture, some- 

 times produced into a canal at the fully gerontic stage. Columella 

 smooth. Operculum paucispiral, with subcentral nucleus. 



Nearly two hundred species are now known, inhabiting the West 

 Indies, Europe, Indian Ocean, Polynesia, and Australasia. 



Fossil. Tertiary. 



These molluscs often attain a considerable size before losing their 

 larval characters, particularly when distant from the shore. 



KEY TO SPECIES. 



A. Keels smooth or but slightly nodulous ; colour light brown . . Huttoni. 



B. Keels more or less distinctly gemmate. 



a. All the adult whorls with 3 keels, axial and spiral sculpture of 



about equal strength . . . . . . . . lutea. 



an. Adult whorls first with 2 then with 3 keels. 



6. Outlines of spire convex ; shell chequered with brown 



and white . . . . . . . . . . ampulla. 



bb. Outlines of spire straight or but very slightly convex. 

 c. Gemmules not prominent, 18 to 20 on a whorl; shell 



white . . . . . . . . . . infelix. 



cc. Gernmules very prominent, high, lower whorls with 



a median fulvous band, base fulvous . . . . fascelina. 



1. Triphora ampulla, Hedley, 1902. Plate 15, fig. 2. 



Tripliora ampulla, Hedley, P.L.S. N.S.W., 1902, 615, pi. 33, f. 38, 39. 



Shell small, narrowly conical, acuminate. Sculpture : On the first 

 four adult whorls are 2 gemmule rows ; on the fifth a small median 

 row is intercalated, which increases till at the last whorl it equals the 

 others ; the gemmules are about 18 to a whorl, large and closely set, 

 linked within the row but not vertically ; a suprasutural keel below 

 the periphery of the last whorl ; 2 plain keels upon the base. Colour : 

 Each whorl is chequered by alternate squares of white and chocolate ; 

 apex white ; base chocolate. Spire high, a little less than five times 

 the height of the aperture ; outlines moderately convex. Protoconch : 

 First whorl smooth, the other three bicarinate, crossed by fine bars. 

 Whorls about 13, regularly increasing, flattish ; base slightly concave. 

 Suture distinct. Aperture subquadrate, angled above, produced below 

 into a short, straight, and narrowly open canal. Outer lip sharp, with 

 a simple sutural notch ; spur of the basal lip not reaching the pillar. 

 Columella short, vertical, slightly concave, terminating in a point at 

 the inner margin of the canal. Operculum unknown. 



Diameter, 1-6 mm. ; height, 5 mm. (type). 



Animal unknown. 



Type in the Australian Museum, Sydney. 



Hob. Takapuna and Narrow Neck Keefs (H. S.) ; near Little 

 Barrier Island, in 20 fathoms (R. H. Shakespear). 



The type is from Watson's Bay, Port Jackson. 



