204 



PKOCEEDINGS OF THK MALACOLOGICAL SOCIETY. 



Found mostly with the preceding species, from wliicli it is not 

 always easily separated. 



9. MONODONTA PORCIFEEA (Watson). 



'i Lahio porcifera., A Adams: Proc. Zool. Soc, 1851, p. 179. 



Trochus [Biloina) porcifcr (A, Ad.) : Watson, liept. Challenger 



Exped., Gastropoda, p. 67, pi. iv, fig. 12. 

 Diloma nigerrima, Chemn. : Hntton, Man. New Zealand Moll., p. 90 ; 



? Hntton, Trans. Kgav Zealand Inst, vol. xv, p. 125, 



pi. XV, fig B (radula). 

 Monodonta nigerrima (Chemn.) : Hntton, Proc. Linn. Soc. New Sonth 



Wales, vol. ix, p. 360 [not nigerrima (GmeL), Philippi]. 

 Monodonta forcifera, Watson : Pilsbry, Man. Conch., ser. i, vol. xi, 



p. 102, pi. xxii, figs. 53, 54. 



Shell depressed, globose, blnish-black, polished, siiperficially Urate, 

 sometimes sparsely dotted with white. Suture margined below. 

 Outer lip margined with black. Columella not dentate, broad, sub- 

 concave. Opaque substance of columella extending upon the base of 

 the aperture, forming a strong ledge within. Alt. 10-13, diam. 

 13-5-16-5mm. 



My specimens do not show a trace of white spots, but otherwise 

 agree with Watson's description. Monodonta coracina also occurs, with 

 and without yellow spots. 



Portion of radiila of Monodonta porclfera ("Watsou). 



The figures of the teeth of the radula of Diloma nigerrima published 

 by Captain Hutton, and quoted above, are very likely those of another 

 species [Monodonta coracina 'i). I therefore give here the figures of 

 the teeth of specimens which I consider to be typical, collected at 

 St. Clair, near Dunedin. 



Hai. — The only specimens I have seen and collected on rocks arc 

 those fi'om St. Clair, Dunedin. Captain Hutton quotes the following 

 localities : Eanks' Peninsula to Dunedin, Chatham Is., Auckland Is. 



10. Monodonta cor.acina (Trosch.). 



Trochiis coracinus, Troschel in Philippi : Conch. Cab., p. 148, t. xxiv, 



fig. 13. 

 Monodonta coracina (Ti'oschel) : Pilsbry, Man. Conch., ser. i, vol. xi, 



p. 103, pi. xix, fig. 94 ; ])1. xxxi, fig. 28. 



