58 PEOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



all the other known forms, has a thread-like keel on each side of the 

 labrul slit, and these are continuous iip the spire almost to the apex. 

 On the contrary, in the present species, the slit, besides being very 

 short, is not ridged and keeled. Another peculiarity of S. Zyttelton- 

 ensis is the presence of colour in the shell, which in other members of 

 the genus is almost constantly whitish. S. ohliqua, Watson, from 

 Kergueleu Island, is smooth, but differs fi-om this species in form, 

 and in the slit, which is traceable much further up the spire. The 

 rate of increase is much more rapid in S. Lytteltonensis than in 

 S. ohh'qua, and consequently the body whorl is much larger in 

 proportion to the spire than in the latter form. 



PnoTixuLA SuTEEi, n.sp. PI. YII. Fig. 3. 



Testa minuta, imperforata, turbinata, diverse colorata, omnino 

 nigrescens, nigra, albo variegata et radiata, rubra, albo radiata, etc. ; 

 anfractus 5 convexi, celeriter crescentes, spiraliter obscure striati, 

 lincisque incrementi obliquis tenuissimis sculpti, ultimus ad peri- 

 pheriam obtuse vel rotunde angulatus, infra in medio subimpressus ; 

 apertura obliqua, rotuudata, longit. totius | ada?quens. intus iridescens ; 

 peristoma pallidum, marginibus callo tenui junctis, columellari arcuato, 

 incrassato, reliexo. Diam. maj. 4, min. 3 mm. ; alt. 4 mm. ; apertura 

 2 mm. lata. JIab. — Lyttelton Harbour, JSTew Zealand (collected by 

 H. Suter). 



The genus P/wtinida is mainly Antarctic in its distribution, for, of 

 the seventeen species recorded (some of which are doubtfully distinct 

 from one another), thirteen occur in South Patagonia ; two of the 

 remaining four are from unknown localities, one is Japanese, and one 

 from the Sandwich Islands. 



Of the last species, P. sandivichiana, of A. Adams, there are speci- 

 mens in the Cumingian Collection, labelled " New Zealand," and I 

 am inclined to think that they really occur in that locality. 



The present species is much smaller than that form, indeed, the 

 smallest of this group of Trochidce. It is also different in shape, being 

 more conical, with a higher spire. 



It is remarkable for its variation in colour. Some specimens are 

 entirely black, others are black with whitish rays fi'om the suture to 

 the periphery, and not infrequently there is a series of whitish spots 

 or short rays on the middle of the base. In other examples the 

 ground-colour is reddish or pinkish, and is interrupted with pale rays 

 and spots. 



In some respects P. ftisca, A. Adams, the habitat of which is un- 

 known, is very like this species. It is, however, considerably larger, 

 and much more distinctly spirally striated. 



AcM^A Helmsi, n.sp. PL VII. Figs. 4, 5. 



Testa parva, depresse capuliformis, fere la^vis, ceeruleo-cinerea, 

 lineis numcrosis radiantibus tenuibus rufo-nigris picta, infra apicem 

 subterminalem leviter concava, postice convexa, arcuata ; pagina 

 iaiterna viridis, apiccra versus albida, rufo sparsim notata, ad mar- 



