262 GASTROPODA. [Pectinibranchia. 



pointed tubercle on the right side. Head elongated, tentacles very 

 short, eyes at their base outside. The respiratory cavity is ample, 

 branchia yellow, extending exteriorly above the mantle. The whole 

 animal black, with yellowish. 



Type in the Mus. Hist. Nat., Paris. 



Hah, Thames Kiver, in considerable depth, type (Q. & G.) ; 

 Rangitoto Channel, in 4 fathoms (H. S.). 



2. Stephopoma nucleogranosum, Verco, 1904. Plate 15, figs. 7, a, b. 



Stephopotna mtcleogrunosum, Verco, T.R.S. S.Aust., xxviii, 1904, 143, pi. 26, 

 f. 11-13 ; Suter, T.N.Z.I., xxxviii, 328. 



Shell attached, solitary, or conglomerate. Nucleus horn-coloured 

 or white ; nautiloid, of 1 turns ; diaphanous, slightly effuse at its 

 aperture ; covered with minute granules, arranged in crowded lines 

 corresponding with the accremental lines. The shell springs from 

 within the slightly trumpet-shaped mouth, which projects all round 

 and marks off the embryonic shell from the next whorl : 2| of these 

 follow in the same plane, rather rapidly enlarging, and attached to 

 the surface on which the shell rests ; then come 1 or 2 whorls, coiled 

 above and adhering to those below ; and, finally, a free more or less 

 twisted tube, varying up to 1 in. in length, the attached whorls 

 along their outer under-surface throw out numerous scales of attach- 

 ment at irregular intervals. The adherent whorls have a pronounced 

 rounded carfna along their upper outer part, which gradually be- 

 comes less valid along the free tube, until it may be indistinguishable. 

 From this carina the side is flat to the carina of the whorl below, 

 so that a young shell has the shape of a short cylinder fixed by one 

 end on the rock, &c. There are moderately developed accremental 

 strife, which become ruder and rounder on the free tube. Aperture 

 circular, or very slightly elliptical. Colour translucent white ; some 

 are tinged more or less with pinkish-chestnut. Operculum horny, 

 multiannulate ; nucleus central, setigerous. N. ire comparatively 

 narrow beyond the base of attachment, then flatly expanded, with 

 numerous (perhaps 8) fine setse on either side ; beyond these the 

 seta bifurcates one part continues nearly in the same axis, and is 

 the larger and longer ; the other stands out at an acute angle, and 

 generally divides into two. Resting on the operculum, in the throat 

 of the shell, may be 3 or 4 embryos, like minute nautilus. (Dr. Verco.) 



Cylindrical portion about 6mm. in diameter and 4mm. or 5 rnm. 

 high ; aperture, 3-4 mm. in diameter. 



Type in the collection of Dr. J. C. Verco, Adelaide. 



Hab. Takapuna Reef, on the under-side of boulders ; Rangitoto 

 Channel, in about 5 fathoms (H. S.) ; Bay of Islands. 



The type is from Blackstairs Passage, South Australia, in 16-23 

 fathoms. 



Fossil in the Pliocene of Wanganui. 



