Hutton. — On New Zealand Land Mollusca. 203 



T. decidua, Pfeiffer (1857). 



Delicately striated, and with fine membranous plaits ; periphery sub- 

 carinated. Yellowish horny, obscurely marked with reddish. Diameter 

 •3 inch. 



North Island. — Auckland (Cheeseman) ; Wangaruru. 

 Genus Thalassia, Albers. 



Shell conoidal, depressed ; periphery rounded, or carinated ; umbilicus 

 narrow or moderate ; whorls smooth, often with membranous plaits, especi- 

 ally in the young. Jaw with flat ribs. Marginal teeth longer than broad 

 with one point very much longer than the others. 



T. portia, Gray (1849) ; H. kappa, Pfeiffer (1851) ; H. collyrula, Eeeve 

 (1852). 



Periphery rounded ; umbilicus moderate ; whorls with distant mem- 

 branous hairy ribs ; ribs about 12 in the tenth of an inch. Pale brown, 

 obscurely variegated with rufous. Diameter -33 inch. Dentition, 24-1-24. 



North Island. — Auckland (Sinclair, Greenwood, Gillies, Cheeseman). 



When deprived of hairs this shell somewhat resembles Patula lucetta, 

 but it may be distinguished by the narrower umbilicus, and more distant 

 ribs. 



T. obnubila, Keeve (1852); H. sigma and H. lambda, Pfeiffer (1851) ; 

 H. igniflua, Eeeve (1852). 



Periphery sub-carinated ; umbilicus moderate ; whorls finely striated 

 and with distant spiral shallow grooves ; sometimes with membranous plaits. 

 Brownish horny, often banded with reddish brown. Diameter -58 inch. 

 Dentition, 36-1-36. 



North Island. — Napier. 



South Island.— Dunedin (F.W.H.) ; Oxford (Chilton). 



T. propinqua, Hutton (1882). 



Periphery obtusely angled ; umbilicus very narrow ; whorls striated, 

 smooth. Pale horny with narrow undulating bands of reddish brown. 

 Diameter -25 inch. Dentition, 31-1-31. 



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



South Island. — Weka Pass (Chilton) ; Southland (G. M. Thomson). 



T. neozelaniga, Gray (1843). 



Periphery acutely angled ; umbilicus narrow ; whorls striated, smooth, 

 or with membranous plaits in the young. Horny brown, with undulating 

 bands and spots of reddish brown. Diameter *42 inch. Dentition, 

 35-1-35. 



North Island. — Auckland (Sinclair, Greenwood, Cheeseman, Gillies) ; 

 Wellington (F.W.H.) ; Wanganui (T. W. Kirk) ; Napier (Colenso). 



Chatham Islands. 



