Tl><rnsia.\ GASTROPODA. . 659 



striate; the following whorls with fine hair-like retractive and flexuous 

 oblique striae ; the interstices with minute growth-lines and indistinct 

 microscopic spiral striae. Colour corneous to brown, faintly marked 

 with narrow reddish streaks. Epidermis thin, not shining, easily 

 peeling off. Spire conoidal, convex, about two-thirds the height of 

 the aperture. Protoconch flatly convex, of 1 whorls. Whorls 5, 

 flatfish, gradually increasing, the last not descending, subangular ; 

 base flatly rounded. Suture not much impressed. Aperture oblique, 

 rotundly lunate. Peristome simple, straight, margins slightly con- 

 verging, basal ma,rgin rather constricted. Columella short, arcuate. 

 Inner margin obliquely descending, slightly callous, reflexed above, 

 spreading as a thin layer over the parietal wall. Umbilicus narrow, 

 deep, half-hidden by the columellar reflection. 



Diameter Maj., 8mm. ; min., 7 mm. : height. 4-5 mm. 



Animal unknown. 



Type in the British Museum. 



Hob. North Island : Bay of Islands (Hochstetter) ; near Auck- 

 land. South Island : Dune-din (Captain Hutton) ; Dyer's Pass (H. S.) ; 

 Waipara ; Lake Guy on : Castle Rock, Southland ; Waitaki ; Hurunui. 

 Found under stones. 



Remarks. Erroneously reported from Australia. The umbilicus is 

 wider and the periphery more rounded than in the very nearly allied 

 T. decidua. 



5. Therasia Tamora, Hutton, 1883. Plate 9, fig. 7, a, b. 



Therasia Tamora, Hutt,, N.Z.J.S., i, 477 ; T.N.Z.I., xvi, 1883 (1884), 

 182, 202; Hedley and Suter, P.L.S. N.S.W. (2), vii, 641. Gerontia 

 (Therasia) Tamora, Hutt. : Pi]sbry, Man. Conch. (2), viii, 70, pi. 22, 

 f. 49-51. Flammulina (Therasia) Tamora, Hutt. : Suter, J. de Conch., 

 xli, 246 ; Man. Conch. (2), ix. 16. 



Shell small, conical, umbilicated, thin, with membranous ribs 

 and processes. Sculpture consisting of rather distant, oblique, re- 

 tractive membranous riblets, about 5 per millimetre, produced at the 

 periphery into oblong membranous processes with a rounded apex ; 

 interstices with minute growth-lines ; no spiral sculpture. Colour 

 corneous to brown. Epidermis thin, lustreless, very easily rubbed 

 off. Spire conical, rather acute, about the same height as the aper- 

 ture ; outlines lightly concave. Protoconch of li smooth and convex 

 whorls, elevated. Whorls 5. rather flattened, the last not descending, 

 its periphery distinctly angled ; base lightly convex. Suture impressed. 

 Aperture transversely oval. Peristome thin, the margins converging. 

 Outer lip acutely arched ; the basal lip broadly rounded. Columella 

 short, arcuate. Inner lip slightly callous, somewhat expanded, but 

 not reflexed, spreading as a thin callosity over the convex parietal 

 wall. Umbilicus narrow, deep, open. 



Diameter Maj., 4mm. ; min.. 3-5 mm. : height. '2-5 mm. 



Animal unknown. 



