772 GASTROPODA. [Pulmonaia. 



Diameter Maj., llmm.; min., 8-25 mm. : height, 6-25 mm. 

 (type). Diameter Maj., 14mm. ; min., llmm. : height, 7mm. 



Dentition (Hutton, T.N.Z.L, xvi, 167, pi. 10, f. S). Formula of 

 radula 16 + + 16. Transverse row of teeth forming an acute angle. 

 Teeth slender, all aculeate, smooth, increasing from the centre to 

 the 14th, which is the largest, the outer two teeth becoming smaller 



again. 



Type in the Canterbury Museum. Christchurch. 

 Hob. Stewart Island (T. Kirk). 



2. Rhytida citrina, Hutton, 1883. Plate 30, fig. 14. 



Rhytida citrina, Hutton, T.N.Z.I., xv, 1882 (1883), 139 ; xvi, 208 : Hedley 

 and Suter, P.L.S. N.S.W. (2), vii, 031 : Suter, J. de Conch., xli, 286. 



Shell small, depressed, umbilieated, malleated, thin, translucent, 

 shining. Sculpture : The first two whorls radially plaited, with a 

 few distant fine spiral grooves, the following volution malleated on 

 the upper surface, periphery and base with fine growth-lines ; micro- 

 scopic dense and distinct spiral lines are present on the last whorl, 

 becoming obsolete on the base ; a few distant spiral lines round the 

 umbilicus. Colour pale yellow, sometimes with a spiral brown band 

 on the middle of the upper portion of the whorl ; edge of peristome 

 and umbilicus brown. Spire very flatly convex, apex obtuse. Proto- 

 conch of 1^ turns. Whorls 2|, rapidly increasing, convex ; periphery 

 and base rounded. Suture impressed. Aperture oblique, broadly 

 oval. Peristome very thin, convex. Columella subvertical, arcuate. 

 Inner Up refiexed above. Umbilicus rather narrow, infundibular, 

 deep. 



Diameter Maj., 7-75 mm. ; min., 6 mm. : height, 6 mm. 



Animal pale brown, the upper surface with the peduncles and 

 tentacles dark sooty-black, with a pale band on the top of the head ; 

 sides of the foot marbled with sooty-black. (Hutton.) 



Dentition (Hutton, T.N.Z.I.. xvi, 167, pi. 10, f. R). Radula with 

 the formula 17 + + 17. Transverse rows of teeth forming an acute 

 angle. Teeth slender, all aculeate, smooth, increasing in size from 

 the centre to the 15th, which is the largest ; 16th nearly as large as 

 the 15th ; 17th much smaller. 



Type in the Canterbury Museum, Christchurch. 



Hob. South Island : Greymouth, type (Helms) ; Buller River 

 (Haast). 



Remarks, It is hardly possible that this shell can be the young of 

 R. patula, because the markings on the shell, the colours of the animal, 

 and the dentition all differ. (Hutton.) 



The largest of the three type specimens is evidently not adult, and 

 it is not easy to separate this species from R. patula by shell -characters 

 alone. 



