Thermia.] GASTROPODA. 651 



somewhat irregular, close, retractive, flexuous riblets, about 10 per 

 millimetre ; the interstices with fine growth-lines, but not reticulated. 

 Colour from corneous to flesh-colour ; young specimens usually corneous 

 all over, adult shells either reddish at the apex and round the peri- 

 stome or the flesh-colour may extend over the whole shell. ?-'/ 

 depressed conoidal, convex, half the height of the aperture. P/"/i/- 

 conch of 1 whorls, slightly radiately striated. Whorls 5, slowly 

 and regularly increasing, flatly rounded, periphery distinctly angled ; 

 base convex, impressed at the middle. Suture impressed. Aperl'trr 

 oblique, transverse, ovately lunar. Peristome straight, thickened by 

 a pinkish callosity, which unites the very slightly converging margins 

 on the parietal wall as a thin glaze. Columella short. Inner lip 

 oblique, arcuate, callous, renexed above, and usually closing the per- 

 foration ; young shells are narrowly perforated or subpertorated. 



Diameter Maj., 8-5 mm. ; min., 7-5 mm. : height, 5-5 mm. 



Jaw slightly arcuate, with an indistinct median projection inferiorly, 

 with numerous vertical indistinct folds, ends rounded. 



Radula with the formula 29 + 1 + 29 ; laterals about 8. The 

 'riitral tooth longer than broad, tricuspid, median cusp reaching 

 to the end of the base, and its broad short cutting-point over the 

 next row of teeth. Laterals similar to the central. Marginals tri- 

 dentate, broad ; median tooth long and stout, the others small ; outer 

 marginals bidentate. 



Type in my collection. 



Hob. Toko, near StiMtfoH. type (R. Murdoch) ; Upper Wanganui 

 River. 



4. Thermia virescens, Suter, 1899. Plate 25, fig. 20, a, b. 



Flammulina (Pyrrha) viresceiis, Sut., P. Mai. S., iii, 1899, 287, pi. 15, f. 3-7. 



Shell small, globosely depressed, perforate, faintly shining, greenish, 

 thin, semitransparent. Sculpture : Protoconch microscopically very 

 finely decussate ; the following whorls with irregular retractive 

 sinuous plaits ; the interstices with minute growth-strise and distinct 

 close spiral lirae. Colour corneous, with a greenish hue, more distinct 

 on the base. Epidermis thin, transparent, somewhat shining. Spire 

 depressed conoidal, convex, about half the height of the aperture. 

 Protoconch of 1^ flattish whorls. Whorls 4-|-, first slowly then more 

 ra.pidly increasing, flatly convex, periphery rounded, subangled in 

 young specimens ; base convex, impressed at the centre. Suture 

 impressed. Aperture oblique, transverse, ovately lunar. Peristome 

 simple, acute, extremities distant, subconvergent. Columella short, 

 oblique. Inner lip very thin, reflexed above, extending as a very 

 thin glaze over the convex parietal wall. Umbilicus narrow, half- 

 hidden by the columellar reflexion. 



Diameter Maj., 9 mm. ; min., 7-5 mm. : height, 5-5 mm. Dia- 

 meter of the perforation, 0-5 mm. 



