Webster. — Additions to N.Z. Molluscan Fauna. 255 



valve has the tegmentum longer than the breadth, the hooked 

 mucro being slightly post-median ; the area behind it is con- 

 cave, white, composed of oblong granules, bordered on either 

 side by others of longer form, but the same colour. Anterior 

 valve with 5 slits corresponding to the ribs ; median valves 

 with 1 slit ; posterior with many slits, the denticles being mostly 

 bifid. In the type these denticles are perpendicular, and not 

 visible from above ; in other specimens they extend outwards, 

 and may be seen beyond the tegmentum ; in such specimens 

 the mucro is not so prominent, the white area narrower, and 

 composed of long granules like those bordering the oblong gran- 

 ules of the type, these latter being altogether absent, as also 

 are the raised white borders of the valves. It may be that 

 these specimens have not attained their full development, as 

 none of them approach the type in size. Interior blue-green, 

 white towards the edges. Girdle grey-green, leathery, a minute 

 pore at each suture, 4 on anterior valve. The dotted lines on 

 figs. 5 and 7 show the limit of the white granular patch. Figs. 6 

 and 7 represent the posterior valve of a second specimen. 



Length of dried specimen, 35 mm. ; width, 18 mm. 



Hab. — Orua Bay, Manukau Harbour ; on rocks at low tide. 



Type in my collection. 



The type is unique ; seven of the less-developed specimens 

 were found. The apparent hybridism is striking, especially 

 as I have never found A. violaceus on the west coast, though 

 a very small form of A. zelandicus is fairly common. Professor 

 Pilsbry remarks (Man., vol. xv, p. 17) that another species of 

 Acanthochites will probably be found. I have not given the 

 dentition, as it is of little value in determining the position of 

 species or genera of the Placophora. 



Named after my wife, who is an enthusiastic collector. 



Tornatina oruaensis, n. sp. Plate XX, figs. 12-15. 



Shell cylindrical, white, of 3 J whorls, slightly concave in the 

 crown, above the centre of which projects the smooth proto- 

 conch, tilted at an angle of somewhat less than 90°. Sculpture : 

 Faint growth-lines, prominent posteriorly, following the curve 

 of the outer lip, the surface scored with fine wavy spiral fur- 

 rows. Suture deep. Type I : Crown hollow, the tilted apex 

 visible above it. Outer lip longer than the shell, advancing 

 in the centre and rounded anteriorly ; columella arcuate, with 

 a thin but distinct labial pad and a very strong fold, which is 

 thickened anteriorly. Type II : Apex subscalar ; aperture 

 shorter than the shell ; columella with a much slighter fold 

 i;han the last. 



