Iredale. — Suter's :i Manual of the New Zealand Mollusca." 421 



dismissed P. campbelli Filhol for lack of figure (p. 1079), but this excuse 

 cannot be urged against Spalowsky's name, as a beautiful coloured repre- 

 sentation accompanies it. I hope to elaborate the relationships of the 

 littoral marine molluscs of South America and New Zealand at some later 

 date, as hitherto not much notice has been given to this fact. 



Plaxiphora zigzag (Hutton, 1872). [P. 19.] 



Forty- odd years ago Hutton described this species, which has only re- 

 ceived its due recognition this year (1914) by myself through indications 

 by Thiele in 1909. In the Revision, p. 23, Thiele's examination of a small 

 shell from Lyttelton led him to point out the differences between this and 

 P. caelata Reeve. As the specimen seemed young, Thiele fortunately 

 withheld nomination. When I was collecting at Lyttelton I was always 

 puzzled at the association of all the small Plaxiphora under the one name, 

 caelata Reeve. A smaller shell, differently coloured, with a peculiar girdle, 

 was more common, but almost always in an unrecognizable state as regards 

 valve sculpture. The larger, clean, easily determined P. caelata Reeve lived 

 lower down, and was much more rare. I collected numbers of the former 

 in the desire to secure good-looking specimens. Dissection of many of 

 these showed them constantly to give the characters noted by Thiele as 

 differentiating his unnamed form from P. caelata Reeve. In the Proc. 

 Mai. Soc. (Lond.), vol. xi, p. 34, 1914, I recorded the fact that no new name 

 was needed, as this was the species described by Hutton in 1872, and this 

 must be added to the New Zealand list, and the name removed from the 

 synonymy of P. caelata Reeve. Hutton's description is very good as regards 

 external features, and the shell can be recognized by means of it. 



Suter (p. 1078) remarks that P. terminalis may be classed as a subspecies 

 of P. caelata ; but that conclusion was not intended by my remarks. My 

 reading of Thiele's description and figures of P. schauinslandi led me to 

 decide that agreement with P. terminalis was certain, laying no weight 

 upon locality. The Chatham Island species, which I have not seen, would 

 appear to differ, though it is difficult to judge from descriptions, and, if so, 

 would bear Thiele's name. 



Plaxiphora glauca (Quoy and Gaimard, 1835). [P. 20.] 



What the species included under this name is I do not know. It cannot 

 bear this name, as it undoubtedly cannot be the Australian species thus 

 named, for which the correct name is P. albida Blainville, as noted by Suter 

 on p. 1079, but rejected as unfigured. " The latter [glauca Q. & G.] can 

 still be retained," Suter writes; but that is not so, as the name is pre- 

 occupied as corrected by Thiele. 



Thiele also named P. schauinslandi from the Chathams, and this may 

 be Suter's species. The coincidence of locality and description forces the 

 conclusion, though P. schauinslandi is referable to the group I have called 

 Maorichiton, while the true P. albida is a member of the Poneroplax group. 

 I propose to substitute Thiele's name for the doubly invalid one selected 

 by Suter, and ask for confirmation. 



I have expressed my views with regard to the genus Plaxiphora in the 

 Proc. Mai. Soc. (Lond.), vol. xi, pp. 31-33, 1914, and have separated the 

 species P. obtecta Pilsbry, with generic rank. I have distinguished five 

 subgenera in the genus Plaxiphora, and would insist upon their usage. 

 This necessitates more careful examination of the species and study of 



