Iredale. — Suter's " Manual of the New Zealand Mollusca." 449 



A series of species show a spiral sculpture only, the above-named being 

 all clathrately sculptured. These differ in other details, but the association 

 hereafter mentioned does not seem natural. Rissoa suteri Hedley is the 

 only Neozelanic example. This is classed by Suter in Onoba, but neither 

 it nor the other species so classed by Suter, R. foliata Suter, have much 

 in common with the type of Onoba. This species, striata Montagu. I have 

 collected in Devonshire. England, and it accurately agrees conchologically 

 with the shells named by Webster R. candidissima and R. carnosa. The 

 confusion present in Suter's arrangement can be gauged from the fact that 

 the former is placed in the genus Rissoa under the subgenus Alvania, whilst 

 the latter appears in the genus Rissoina under the subgenus Moerchiella. 

 Yet both are typically Onoba, not like the species Onoba glomerosa Hedley, 

 somewhat atypical. Ceratia is invalidated by the prior Ceratias. 



Otherwise the shells so classed by Suter agree fairly well. The group 

 is well represented, and might be regarded as a subgenus of Onoba, and 

 would include most of the species placed by Hedley in Onoba. 



Cingula is utilized for a series of species which may not be congeneric, 

 but they certainly differ generically from the type of Cingula, a shell I 

 collected numerously in Devonshire, England. Hedley has classed these 

 in Amphithalamus, but his association of species differs from mine. 



Setia cannot be resorted to for the " featureless " Rissoids, as it is 

 preoccupied. It has been subdivided many times by European mala- 

 cologists, and I will discuss the names hereafter. 



Amphithalamus is a name I have a great dislike to, as it was given to a 

 North American species, and the austral species so called have an austral 

 name already available. 



Anabathron was proposed for an Australian species, and the group is 

 confined to austral seas, as hereafter observed. 



Haurakia gen. no v. 



This genus-name is. provided for the species agreeing with Rissoa hamil- 

 toni, which I name as type. I introduce this genus with some diffidence, 

 as the species is conchologically quite close to Turboella Gray. The mouth 

 of the type species of that genus disagrees, and it runs into quite a different 

 form, named Zippora, which again varies, and has been generically named 

 Rissostomia. The variations that more strongly recall the austral group 

 have been named Apicularia and Pusillina, both by Monterosato, whilst 

 Sabanaea was used by Monterosato for another, to me indistinguishable, 

 group. 



Apicularia and Pusillina agree very closely, as far as conchological 

 characters go, with Haurakia, but as they appear rather obvious derivatives 

 of Turboella, which differs very appreciably from the Neozelanic forms, I 

 would reject both. 



Merelina gen. nov. 



I propose this name for the shells grouped around Rissoa cheilostoma 

 Ten.-Woods, which I name as type. 



The New Zealand specimens available differ at sight from Sydney shells 

 so named, and I have found species of this genus to be fairlv constant in 

 their characters. The genus extends to Lifu as Alvania pisinna Melvill 

 and Standen, which I collected commonly at the Kermadecs, and is un- 

 doubtedly congeneric. 



15— Trans 



