14 FLAMMULINA. 



F. georgiana Quoy & Gaimard. F. hamiltoni Cox. 



F. trajectura Cox. iii, 264. scrupulus Cox. iii, 46. 



F. wynyardensis Petterd. spoliata Cox. iii, 46. 



stephensi Cox. iii, 46, 262. 



Subgenus GERONTIA Hutton. 



Gerontia HUTTON, Trans. N. Z. Inst. xv, p. 135. Gerentia 

 (typog. err.) in N. Z. Journ. of Sci. i, p. 476. 



Shell depressed and openly umbilicated, having the contour of 

 Patula ; thin, rather fragile, the surface delicately sculptured with 

 fine cuticular riblets. Apical whorl minutely granular, or showing a 

 few weak spirals, having a minute perforation at the tip. Type F. 

 pantherina Hutton, pi. 3, figs. 1-3. 



Animal heliciform, mantle rather posterior, included ; tail acute 

 with a mucous pore but no papilla. 



Jaw vertically striated (pi. 2, fig. 5, F. pantherina.) 



Dentition : central teeth tricuspid, cusps with moderate cutting 

 points. Laterals similar, but the ectocones larger than the ento- 

 cones ; transition teeth bicuspid by fusion of entocone with meso- 

 cone. Marginals with a broad bifid cusp (pi. 2, fig. 4, F. panther- 

 ma.) 



The shell is like a thin Selenites with delicate close riblets. It is 

 more broadly umbilicated than in the other subgenera of this genus. 

 The two species are from New Zealand. 

 F. pantherina Hutt. viii, 65. F. Cordelia Hutt. viii, 66. 



Subgenus ALLODISCUS Pilsbry, 1892. 



Psyra HUTTON, Trans. N. Z. Inst. xvi, p. 201, 1884. First species 

 P. dimorpha. Not Psyra Stal, 1876. Allodiscus PILSBRY, Nautilus 

 vi, p. 56, Sept. 5, 1892 ; Man. Conch. (2), viii, p. 66. 



Shell thin, orbicular and depressed, with low or fiat spire, rounded 

 periphery, and narrow or subimperforate umbilicus ; surface radially 

 rib-striated, not hairy, the embryonic H whorls spirally striated (pi. 

 3, fig. 12, F. tullia). Aperture crescentic scarcely oblique ; per- 

 istome thin, shortly reflexed at the columella; parietal wall nude. 

 Type H. dimorpha Pfr. (See pi. 3, figs. 4, 5, 6, F. planulata Hutt.) 



Jaw slightly arcuate, not tapering toward the ends, flatly ribbed 

 or plaited (pi. 2, fig. 11, F. tullia ; pi. 2. fig. 13, F. godeti.) 



Dentition : central tooth with tricuspid reflection, mesocone long. 

 Lateral teeth bicuspid, the entocone being suppressed, or tricuspid. 



