Ehytida.\ GASTROPODA. 773 



3. Rhytida Dunnise, Gray. 1840. Plate 49, fig. 11. 



Helix Dunnice, Gray, A.M.N.H. (1), vi, 1840, 317 ; Dieff. N.Z., 247 ; Revue 

 Zool.. vii, 375;' Conch. Icon., vii, |.i. 80, f. 425: M.H. Viv., i, 207; 

 Hector, Cat. Land Moil. N.Z., !! ; Ereb. & Terr., 1, pi. 1, f. 7 ; Conch. 

 'ah. (2), i, pt. 2, pi. 127, f. 33-35; M.N.Z.M., Ib. Rhytida Dunma, 

 <Jray : Button, T.N.Z.I., xvi, 208 ; Man. Conch. (2), i, 126, pi. 24, f. 73 ; 

 Hed'ley and Suter, P.L.S. \.S.\V. (2). vii. (>30 ; Suter, J. de Conch., xli, 

 285. 



Sh< I! depressed, umbilicated, fuscous, keeled, granularly striated, 

 very faintly shining, rather thin, translucent. Sculpture of proto- 

 conch consisting usually of a few radiate striae and distant spiral lines ; 

 succeeding whorls with oblique elongately granular wrinkle - striae, 

 which are becoming smooth on the base toward the umbilicus, where 

 a few distant interrupted spiral lines are present. Colour fuscous. 

 Epidermis thin, diill on the upper surface, but shining on the base. 

 Spire lightly elevated, obtuse, broadly convex. Protoconch of 1} 

 turns, flatly rounded, slightly darker coloured. Whorls 4 to 4^, flat- 

 tened : the periphery acutely keeled ; base convex, subangled around 

 the umbilicus. Suture not much impressed. Aperture oblique, trans- 

 versely oblong, laterally extended. Peristome simple, superior margin, 

 depressed. Outer lip sharply angled ; basal lip regularly and broadly 

 arched. Columella short, oblique, arcuate. Inner lip somewhat cal- 

 lous and shortly reflexed ; parietal wall with a very thin polished 

 glaze. Uwbilicus moderate, infundibular, deep, cylindrical or slightly 

 gradate. 



Diameter Maj., 24mm.; min.. 20mm.: height. 11 mm. (type). 

 Diameter Maj., 30mm.; min.. 25 mm. : height. 16mm. (large 

 specimen). 



Aiu'mal unknown. . 



Type in the British Museum. 



[lab. North Island : Whangaroa ; Kamo (C. Cooper) ; Whanga- 

 rei (Musson) ; Bay of Islands (Colenso) ; Otonga East (Hawkins) ; 

 Rawene, Hokianga (R. Murdoch) ; Hen Island (Pycroft) ; Waitakerei 

 Range (H. 8.) ; Auckland (Gillies) ; Thames (Adams) ; Ho wick 

 (Major Broun). 



Var. (3, Pfeiffer, 1835, M.H. Viv., iii, 160. 



Rhytida Dunnice, var. (3, Man. Conch. (2), i, 126. 



Shell olivaceous brown, last whorl with 5 elevated close spiral 

 striee below the periphery. 

 Hab. North Island. 

 I have not seen this variety. 



4. Rhytida duplicata, Suter. 1904. Plate 30, fig. 15. 



Rhytida duplicata, Suter, P. Mai. S., vi, Sept. 1!)04, 155, f. 13 in text. 



Shell convexly depressed, umbilicated, carinated, with a ridge 

 above the keel. Sculpture : The surface of the shell is rather irre- 



