SuTEK. — On Neic Zealand Molbisca. 301 



cutting-points, reaching near the posterior end of the base. 

 In the outer laterals the inner cutting-point attains a greater 

 length. 



Marginals tridentate, first broad with strong denticles, 

 then gradually getting longer and narrower, with the denticu- 

 lations on the outer side. Last marginal minute, unidentate. 



Realia egea, Gray. From Forty-mile Bush, North Island. 



Plate XXIII. , fig. 57. 



Badula long, ribbon-like, consisting of about 100 transverse 

 rows of teeth, 3 — 1 — 3. The laterals are fixed in an oblique 

 line running backwards under an angle of 45° to the rhachi- 

 dian line. 



Central tooth as long as broad, constricted in the middle ; 

 anterior part very broad, oval, with seven denticles, of which 

 the median bears a broad blunt cutting-point ; posterior part 

 much smaller, about one-half the breadth of the anterior, with 

 one denticle in the middle. 



First lateral broad and oval anteriorly, with a short stalk 

 and five denticles. Second lateral much like the first, but 

 broader posteriorly, and the sides more straight ; with four 

 denticles, of which the two innermost are sometimes united 

 in one. Third lateral club-shaped, with two deep notches on 

 the inner side, thus rendering it tridentate. Two minute 

 denticles may be observed on the anterior rounded end. A 

 ridge runs down on the interior side. 



*t)^ 



Hydrocena purchasi, Pf. From Forty-mile Bush, North 



Island. Plate XXIIL, figs. 58, H.P., H.C. 



Badula ribbon-like, consisting of very numerous transverse 

 rows of teeth, co.l.(l + l + l).l.oo. The side-teeth running 

 backwards at a sharp angle to the median line. 



Central teeth three, hyaline, very difiicult to be seen ; they 

 are distant from one another, long and narrow, with one re- 

 flection on each. 



Laterals long and narrow, with a short tooth-like projection 

 on the middle of the inner side. 



Marginals rectangular, much longer than broad, with a 

 denticulated reflection on the anterior side. They are very 

 numerous, and diminish gradually in size towards the margin. 



This is the typical radula of the genus Hydrocena, and 

 there is now no doubt possible about the generic position of 

 our minute mollusc. Moreover, for comparison, I give draw- 

 ings of the operculi of H. cattaroensis (H.C.) and H. jmrchasi 

 (H.P.), showing their apophysis and striations. 



