lidorn.\ GASTROPODA. 61. *> 



Hob. Rivers, creeks, and ponds near Christchurch ; Greyniouth ; 

 Pelorus River ; Wellington ; Toko ; Lakes Virginia and Westmere, 

 near Wanganui ; pond near Lake St. John, Auckland. 



Remarks.- A very variable species, but always characterized by 

 the spiral lirse and the effuse basal lip. also by the bristles on the 

 carina. 



Subsp. conferta, Suter, 1905. Plate 24, figs. 20, 20o. 



Isidora lirata conferta, Suter, T.N.Z.I., xxxvii, 1904 (1905), 275, f. 7, <S 

 (reversed) ; xxxviii, pi. 19, f. 7, 8. 



Shell globosely ovate, sinistral, corneous-translucent, thin, almost 

 imperforate. Sculpture consisting of microscopic fine regular and 

 close spiral lirae, with distant lines of growth, which on the upper 

 whorls are rather equidistant. Colour very light horny to light olive- 

 brown. Spire short, broadly conic, about half the height of the aper- 

 ture. Protoconch acuminate, of darker colour, consisting of 2 whorls 

 with fine incremental striation. Whorls 4, either strongly shouldered 

 or having only a posterior angle, which usually gets lost on the body- 

 whorl ; the latter forms the greater part of the shell, is ventricose 

 and convex ; base rounded. Suture impressed. Aperture vertical, 

 elongately oval, acuminate above and produced anteriorly. Outer 

 lip regularly rounded, thin and sharp. Columella slightly arcuate, 

 with a distinct fold above. Inner Up thin, narrowly reflexed over the 

 pillar above, leaving a minute umbilical chink; continued as a thin 

 cr.llosity over the convex parietal wall. 



Diameter. 7mm.; height, llmm.: aperture, 4mm. by 7mm. 

 Mean proportion of diameter to height, 1:1-6. Mean proportion of 

 diameter to height of aperture, 1:1-7. Mean proportion of height, of 

 aperture to height of shell. 1 : 1-6. 



Animal unknown. 



Type in my collection. 



Hob. Swamps near Otorohanga' King-country (type) ; Wairau 

 River, south of Birch Hill Station, Nelson (E. Suter). 



Remarks. - - This subspecies is distinguished from the species by 

 its ventricose form and the much broader aperture, approaching 

 S. tabulata. Gould. 



4. Isidora novse-zelandiae, Sowerby, 1873. Plate 24, fig. 21. 



Physa novcu-zelandicR, Sow., Conch. Icon., xix, f. 29; Button, M.N.Z.M., 

 30. Isidora novce-zelandice, Sow. : Suter. T.N.Z.I., xxxvii, 273, f. 4 

 (reversed) ; xxxviii, pi. 19, f. 4. 



Shell moderately large, oval, imperforate or narrowly rirnate, 

 whorls angled or smooth, thin and fragile. Sculpture consisting of 

 inconspicuous growth-lines only. Colour chestnut, young shells light 

 brown. Epidermis thin and slightly shining. Spire but little ele- 

 vated, conoidal, its height less than half the height of the aperture. 

 Protoconch small, pointed. Whorls 3 to 4, shouldered or convex, th 



