70 GASTROPODA. [Aspidobranchici. 



Remarks. The specimens selected as the type by the late Captain 

 Hutton represent really an extreme form of the species, the high 

 conical and rounded shape being no doubt due to environment ; it 

 has a striking likeness to the figures given by Quoy and Gaimard, 

 but when specimens are compared there can be no more doubt that 

 the New Zealand form is quite distinct from the much larger, more 

 solid, and somewhat differently coloured Australian species. 



I have specimens from Tasmania which correspond exactly with 

 A. parviconoidea. The variability of this species in shape and colour- 

 ing is considerable. 



Var. leucoma, Suter, 1907. 



Acmcea parviconoidea, var. leucoma, Suter, P. Mai. S., vii, 1907, 322. 



Shell small, thin, opaque, depressed conoidal. Sculpture, if any, 

 lost by erosion. Colour white. Apex obtuse, at about the anterior 

 fourth or fifth. Inside white ; central area greenish-white ; margin 

 sharp, with a few small brown dots. 



Dentition unknown. 



Type in my collection. 



Hob. Heathcote Estuary, near Christchurch, type (H. S.) ; Dun- 

 edin Harbour (Iredale). 



Var. nigrostella, Suter, 1907. Plate 5, fig. 14. 



Acmcea parviconoidea, var. nigrostella, Suter, P. Mai. S., vii. 1907. 322, 

 pi. 27, f. 26-29. 



The young shell reveals under a good lens distant low radiate 

 riblets and fine concentric growth-lines. The colour is white, the 

 centre being occupied by a purplish-black 4- to 9-rayed star ; there are 

 sometimes 2 short posterior marginal rays ; round the apex a few con- 

 centric rows of small, oval, vivid blue spots. Inside white ; central 

 area purplish-black, sending off 4 to 9 rays towards the margin. The 

 adult shell has lost all its sculpture ; the colour markings on a whitish 

 ground consist of 2 lateral and 2 posterior black rays, descending 

 from the apex and extending over only a short distance ; the margin 

 is adorned with numerous short black lines. Inside yellowish-white, 

 the central area occupied by the now distorted star of purplish-black ; 

 margin sharp, with a broad border rayed with black. 



Length, 10 mm. ; breadth, 7 mm. ; height, 5 mm. (adult speci- 

 men). Length, 4mm.; breadth, 3mm.; height, 1-5 mm. (young 

 specimen). 



Dentition unknown. 



Type in my collection. 



Hob. Titahi Bay, Cook Strait, type (Miss Mestayer) ; Banks 

 Peninsula (Iredale) ; near Taumaki Island, in 10 fathoms (Captain 

 Bollons) ; Bay of Islands (J. C. Anderson). 



