Iredaee. — Suter' s " Manual of the New Zealand Mollusca." 433 



recognizable cause for the repetition of distinct forms in separate localities. 

 An easily determined form is Cellana radians var. jlaca Hutton. This 

 beautiful shell is common a.t Napier, and lives upon the red sandstone rocks, 

 into which it makes hollows, so that it is difficult to detach without cutting 

 the rock away. Upon the black hard rocks intermingled dark shells are 

 found, and I believe that this yellow form will only be obtained when the 

 soft red rocks are available for its development. Perfectly coloured shells 

 are rare, as might be anticipated. 



Montfortula gen. nov. [P. 100.] 



Under the genus-name Subemarginida Blainville, 1825, three New Zealand 

 species are named, two sections being admitted. This nomenclature and 

 classification is incorrect, though Suter is not to blame in the matter, as 

 he simply followed the " Manual of Conchology," wherein the species of this 

 family were monographed by Pilsbry twenty-odd years previously. It is 

 quite remarkable that no corrections have been made since Pilsbry's work 

 was published, and it has apparently been accepted by most workers with- 

 out question. 



Firstly, the genus-name Subemarginida Blainville, 1825, was accepted. 

 Upon reference to the place quoted (Man. Mai., p. 501, 1825) the name does 

 not occur, but there is only a section of the genus Emarginula named " Les 

 Subernarginules." Such an introduction of a vernacular is not recognizable, 

 and it was necessary to trace the first user of the latinized form Sub- 

 emarginida. This search resulted in Gray, Proc. Zool. Soc. (Lond.), 1847, 

 p. 147 ; type, Patella octoradiata Gmelin. This is not the type named by 

 Pilsbry — viz., Emarginula emarginata Blainville — but there is no question 

 that Subemarginida must date from Gray, 1847, with Patella octoradiata 

 Gmelin as type, upon the present facts. Hemitoma Swainson (" Treatise 

 Malacology," pp. 244, 356, 1840), with H. tricostata Sw., Sow. Gen., fig. 6, 

 was the next synonym, but this appeared to be preoccupied by Hemitoma 

 Rafinesque, 1820. Rafinesque, however, proposed Hemiloma, and Hemi- 

 toma was only one of-Agassiz's gratuitous manuscript corrections ? quoted 

 by Scudder. This species is congeneric with Blainville's E. emarginata, and 

 would be the earliest name for the association grouped by Pilsbry under 

 " Subemarginida." 



At this point it became necessary to study the shells, which I casually 

 knew, more carefully, to determine the groups, as it became obvious Pilsbry's 

 grouping was faulty. 



Clypidina Gray, 1847, was used by Suter as the sectional name for 

 " rugosa Qiioy and Gaimard." I collected many specimens of this shell 

 at Sydney, New South Wales, and Caloundra, Queensland. I also procured 

 examples of Patella notata Linne at Colombo, Ceylon. This shell is the 

 type of Clypidina which was introduced by Gray in the Proc. Zool. Soc. 

 (Lond.), 1847, p. 147. These are entirely different in every manner, and 

 do not show the " internal groove distinct, ending in a short anterior notch," 

 which is given by Suter as the character of the section. The groove is so 

 indistinct that very recently specimens of this Linnean species (Syst. Nat., 

 ed. x, p. 784, 1758) were determined by a well-known conchologist as a new 

 species of Acmaea! This memo should indicate how unlike Clypidina is 

 to the other " subemarginuloid " shells. I regard this as a distinct mono- 

 typic genus, and it is so classed in the British Museum. 



I also consider Tugalia, notwithstanding Pilsbry's opinion, should also 

 rank as a distinct genus, the animal as well as the shell showing good 



