374 PROCEEDINGS OF THK MALAC0L0GIC4L SOCIETY. 



What slioiild be considered tlie type of tliis heteroj^eneous mixture 

 requires a little consideration. In the Proc. Zool. Hoc. Lond., 1H47, 

 p. 170, Gray, heinp; in a quandary, wrote: "(?) Microci/stis, Eeck. 

 ? Uelicolimnx, sp. Ferus. M. ^'x^^^^cula.'''' It would seem, in face 

 of the data given, that this type-designation can be ignored. 



In 1860, in Die Ileliceen, 2nd ed., p. 49, Microcystis, Beck, is 

 included, and " Typus : II. ornatelhi, Beck" definitely stated. 

 I should therefore conclude that this might he accepted, and Microcystis 

 thus retained in the conventional usage. Accepting or^iatella as the 

 type of Microcystis, I would not recognize Kerinadeci as congeneric 

 unless that generic name was used with a very wide significance. 

 For the purposes of zoogeographical study genera of wide limits are 

 valueless, and I therefore do not adopt them. The transference of 

 the species to H/acrochlamys cannot be defended, as Godwin-Austen 

 has shown that the only species really referable to Macrochlamys 

 (save a Mauritian form, probably introduced) are confined to India. 

 The only other generic name suggested in connexion with this species 

 was Microcystina, Morch, wliich, however, was founded on a Nicobar 

 species, and is quite unsuitable for the Kermadec shell. Granting 

 that lurmadeci might prove from animal characters to be referable 

 to Blicrocystis, seiisu lato, the shell characters deserve recognition by 

 some other name, especially as typical Microcystis occur on Norfolk 

 Island. I have therefore introduced the new name given above, and 

 have assigned to it full generic rank until such time as the animals are 

 dissected and compared with the type of Microcystis. 



KiECONCHA Kermadeci (Pfeiffcr). 

 Helix Kermandeci, Pfeifler, Proc. Zool. Soc. Lond., 1856, p. 326. 



Unh. — Sunday Island, Kermadec Group. Living under rotten 

 nikau leaves and rotten wood on the ground. 



Pfeiffer's description reads '^ turbinata^\ and the measurements are 

 given as diam. maj. 3§, min. 3^ mm. ; alt. 22 mm. This suggests 

 an immature specimen, and the type, still preserved in the British 

 Museum, though in imperfect condition, confirms that suggestion. 

 Tlie adult is conical, reci^Uing TrocJwnaninti, but the last whorl is not 

 keeled and the base is rounded. I counted six wliorls regularly 

 increasing and descending ; the aperture not oblique, almost regularly 

 broadly sublunate ; columella nearly vertical, somewhat expanded; 

 no umbilicus. 



Genus PTrcHODON, Ancey. ->. 



Ptyclmlon, Ancey, Bull. Soc. Mai. France, vol. v, p. 372, 188y. 



Type (by original designation), Helix leioda, Hutton. 



The correct attachment of the Polynesian, jSTeozelanic, and Australian 

 ' Endodonts ' is difficult. It is somewhat strange that much of the 

 confusion seems due to the action of the maker of modern terrestrial 

 malacology. Thus Pilsbry, when he evolved order out of chaos in his 

 monumental Guide to the Helices, wrought some little confusion in 

 this group by lumping all the Polynesian ' Endodonts' in Endodonta. 

 He has been somewhat slavishly followed by later writers who have 



