Thalassohelix.] GASTROPODA. 631 



strongly striated with oblique flexuous growth-lines. Colour pale- 

 horny, with numerous narrow zigzag red bands, which are often 

 broken up into a series of bands. Spire convexly conoidal. about 

 two-thirds the height of the aperture. Protoconch of 1^ whorls, obtuse. 

 Whorls 4 to 5, rather flattened, periphery of last whorl acutely angled ; 

 base rounded. Suture impressed. Aperture oblique, rotundly lunate. 

 Peristome thin and sharp, regularly arched, the outer lip sometimes a 

 little angled, Columella short, oblique, arcuate. Inner lip reflected 

 above. Umbilicus very narrow and deep, about one-fourteenth of 

 the greatest diameter. 



Diameter Ma]., 6 mm. ; ruin., 5 mm. : height, 4 mm. (type). 



Dentition. Hutton, T.N.Z.I., xvi, 169, pi. 10, f. G ; pi. 11, f. V. 



Jaw arcuate, not tapering, with about 22 flat plaits, which slightly 

 indent the concave margin. 



Raditla having the formula 11) + 12 + 1 + 12 + H>. Central tooth 

 with a mesocone ; the inner laterals like the central tooth, the ouiei 

 ones bicuspid ; outer marginals with an aculeate mesocone only. 



Tt/pe in the Canterbury Museum, Christchurch. 



Hab. North Island : Auckland (Gillies) ; Hawke's Bay (Colenso) : 

 Otaki Goige (Preston) ; Waimarama ; Portland Island ; Gisborne 

 (A. Hamilton). South Island : Weka Pass, type (Professor Chilton) : 

 Southland (G. M. Thomson). 



Subfossil, together with moa-bones and e^-shells. near Petane 

 (A. Hamilton). 



4. Thalassohelix zelandise, Gray, 1843. Plate 25, figs, (i. (\a. (\l>. 



//,//./ (Carocolla) zelandice, Gray, Dietf. N.Z., 247 ; P.Z.S., 1849, 165 ; Revue 

 Zool.. vii, 375 ; .M.H. Viv., i, 81 ; Conch. Cab. (2), i. pt. 2. 468. pi. 156. 

 f. 3-5; Conch. Icon., vii, pi. 129, f. 780; Hector. Cat, Land Moll. N.Z., 7. 

 Xditina. (Thalassia) zelandice, Gray, Nomencl. Hel. Viv., 47. Helix 

 zelandice. Gray, M.N.Z.M., 19. Thalassia neozelanica, Gray : Hutton, 

 T.N.Z.I., xvi, 203 ; Man. Conch. (2), ii, 214, pi. (i3. f. 63, 64; ix, pi. 3, 

 f. 29. Thalassohelix zelandicp, Gray : Hedley and Suter, P.L.S. N.S.W. 

 (2), vii, 637. Flammulinu (Thalassohelix) Zf/>ni</i<r, Gray : Suter, J. de 

 Conch., xli, 254 ; P.L.S. N.S.W. (2), viii, 488 ; " Nautilus," vii, 124. 



Shell perforated, depressed, turbiniform. pale-horny, pellucid, thin, 

 periphery keeled. Sculpture consisting of fine oblique growth-lines, 

 and exceedingly fine close microscopic spiial stria?. ( 'oJmir pale- 

 horny, mostly variegated with rufous streaks and spots, the former 

 sometimes extending over the base. Epidermis thin, very slightly 

 shining. Spire conoidal. convex, its height about two-thirds that of 

 the aperture. Protoconch of 1 whorl, indistinctly microscopically 

 spirally striate. Whorls 5, first slowly then more rapidly increasing, 

 flatly convex, the last keeled ; base convex. Suture not much im- 

 pressed. Aperture Innately ovate, oblique. Peristome simple, acute, 

 angled at the periphery. Columella short, oblique. Inner lip broadly 

 reflexed above. Umbilicus narrow and deep, about one-ninth of the 

 greatest diameter of the shell. 



