202 Macteay Memoriat VoLume. 
The spirit specimen I have before me measures 27 mm. in total length; the 
muzzle projecting about 4mm. in front of the mantle neck-lappet, and the tail 12mm. 
behind the visceral hump. From the sole of the foot to the top of the visceral hump 
is 10mm., and from sole to keel the tail is 44mm. high. From the pulmonary orifice 
to the muzzle measures 10mm. 
The outline of my example somewhat resembles that of the spirit specimens of 
Cystopelta petterdi, Tate, (P.L.S.N.S.W. (2) V. PI. 1. fig. 1), and of Parmella etheridget, 
Brazier, (Rec. Aust. Mus. I. Pl. x1 fig. 1), consisting of a narrow straight foot 
surmounted by an oblong visceral hump. Probably from having been plunged into 
stronger alcohol, my example is more shrunk and the visceral mass rises more abruptly 
than in the “Challenger” specimen. Both probably bear the same relation to the 
living snails as the above-quoted figure of C. petterdi does to the figure subsequently 
published (P.L.S.N.S8.W. (2) VI. Pl. ut. fig. 5). To further illustrate its probable 
appearance in life, and for comparison of the mantle lobes, I add a drawing of its ally, 
Flelicarion robustus, Gould.* 
In death, the mantle, retracted from a heart-shaped space 7mm. wide, exposes 
a portion of the shell; but in life it probably conceals the whole. The shell is that 
shade of sherry yellow common to other of the Hed:carzonine, and, though thin, is 
sufficiently stiff to form a flat roof to the visceral hump. The mantle is finely 
wrinkled and papillate. Though its lobes have grown together much more than in 
FHelicarion, they have not attained the extreme development of Cystope/ta, where the 
shell has entirely disappeared and the lobes are fused together into one seamless 
whole. Neither has P. fischer? reached the stage of Parmella etheridget, where the 
various lobes have become atrophied, for diminutive right and left dorsal lobes are 
still preserved (PI. xxvu. figs. 1,2 aandb). The sides and sole of the foot are a pale 
ochreous-yellow, facial area blackish and the mantle a purplish-brown. The tail, of 
the same height throughout and possessing the usual pedal line and diagonal grooves, 
is sharply keeled and terminates in a large mucous pore cleft to the sole, but not 
overhung by a horn. 
Shell, 164mm. long, 9mm. wide and 5mm. deep, when freshly extracted ; 
rudimentary, thin, transparent, waved and striated concentrically and crossed by faint 
spiral grooves ; somewhat like a finger-nail in shape and texture. Whorls two and 
a-half, rapidly increasing, the mode of growth passing from spiral to straight; the 
last whorl diverging, like a Dolade//a shell, from its predecessor with which a wrinkled, 
* This sketch was made Sept., 1888, from a specimen found at Little Nerang Creek, South Queensland, which is 
thus described in my note-book. ‘‘ Helicavion, sp.—Total length, 46mm. Colour generally light yellow; mucous gland 
brilliant pink, neighbourhood of gland and sole of foot a fainter pink ; tubercles of keel orange ; grooves diagonally across 
the back an intense black; mantle flesh-coloured with irregular black spots. Keel terminating posteriorly in a horn-shaped 
projection above the gland. When extended shows a flat white saddle-like space behind the shell. Tentacles rather long, 
finely tuberculated. ‘The space between the tentacles and the mantle covered with narrow longitudinal tubercles. Mantle 
coarsely papillate, the two lobes completely covering the shell when the animal is undisturbed. Sole of foot divided 
longitudinally by a median area,” 
