FLAMMULINA. 15 



Marginal teeth broad, with 3 to 5 cutting points (pi. 2, fig. 14, F. 

 godeti). In F. tullia the side cusps of the centrals are minute ; 

 inner marginals tricuspid, outer bicuspid (pi. 2, fig. 12, F. tullia; 

 pi. 2, fig. 14, F. godeti). In F. dimorpha the side cusps of the 

 central tooth are minute ; the marginals have a long bifid inner cusp 

 (mesocone, or fused mesocone and entocone), and by splitting, two 

 ectocones. 



F. dimorpha Pfr. ii, 211. F. adriana Hutt. viii, 67. 



F. venulata Pfr. ii, 211. F. miranda Hutt. viii, 68. 



F. cassaudra Hutt. viii, 66. F. godeti Sut. viii, 68. 



F. tullia Gray, ii, 211. F. wairoaensis Sut. 



F. planulata Hutt. viii, 67. F. urquharti Sut. 



Subgenus PYRRHA Button, 1884. 

 Pyrrha HUTTON, Trans. N. Z. Inst. xvi, p. 200. 



Shell depressed-globose, thin, translucent, striated and minutely 

 reticulated, imperforate; the periphery rounded, spire convex. 

 Peristorne simple, reflexed over the minute perforation. Type P. 

 cressida Hutt., pi. 3, figs. 17, 18, 19. 



Animal heliciform, mantle subcentral, reflected over the peristome 

 with an even margin ; tail truncate, with a large papilla and mucous 

 gland. 



Jaw arcuate, flatly ribbed (pi. 2, fig. 9, .P. cressida.) 



Dentition : central tooth with the mesocone only developed. 

 Laterals bicuspid, the entocones suppressed. Marginal teeth with 

 several cusps (pi. 2, fig. 10, F. cressida.) 



The single species inhabits New Zealand. 



G. cressida Hutton, viii, 72. 



Subgenus THERASIA Hutton, 1883. 



Therasia HUTT., N. Z. Journ. of Sci. i, p. 477 (proposed for tamora, 

 Valeria and thaisa.) 



Shell depressed, perforate or umbilicate, thin, with conoidal 

 spire; the periphery angular or subangular ; aperture round-lunar ; 

 lip thin, slightly reflexed at the columella. Surface striated. 

 Embryonic whorls spirally striated. Type T. thaisa Hutton, pi. 3, 

 figs. 14, 15, 16. 



Resembles Allodiscus in the dentition, and the spirally striated 

 apex of the shell, but differs in the form and sculpture of the latter, 

 which is much as in section Thalassohelix. 



