136 
Jaw (pi. xxi., fig. 7) lunate, with stout central rostriform pro- 
jection, smooth, ends square. Radula (pi. xxii., fig. 8) tongue- 
shaped, twice as long as broad ; formula, 120 rows of 90 : 24 : 1 : 
24:90 ; rachidian with a slender lance-shaped median cusp, 
whose cutting point projects beyond the basal plate, bearing two 
small auxiliary cusps half-way along the reflection ; the laterals 
resemble it, except that the outer auxiliary cusp only is developed, 
alate margin of the basal plate rounded ; the numerous marginals 
succeed after one or two transition teeth, and are slender, minute, 
oblique and bicuspidate. The genital system is figured on pi. xxii., 
fig. 5. The spirit specimens before me exhibit a pedal line, well 
developed caudal mucous pore and mantle lobes.* 
3. N. uilli, Cox, 1873. 
Illustrations. Cox, P.Z.S., 1873, pi. 16, figs. 7 a, 7 b ; Try on, 
Man. Conch., ser. 2, Yol, i., pi. 38, figs. 57, 58. 
Descriptions. Cox, P.Z.S., 1873, p. 151 ; Pfr., Mon. Hel. Viv., 
Voi. vii., p. 26 ; Tryon, Man. Conch. 2-1-170. 
Type. The Cox Collection. 
Hob. The summit of Mount Cower. 
Jaw (pi. xxii., fig. 6) lunate with median projection, smooth, 
ends rounded. Radula (pi. xxii., fig. 2) somewhat wedge-shaped, 
almost as broad as long ; formula, 163 rows of 430:24:1 : 24: 430; 
save that the main cusps appear rather longer and more slender 
and project further past the basal margin, the structure of the 
teeth is the same as described for the two preceeding species ; the 
feature of the membrane being the excessive number of minute 
marginals. 
Sophice, lioivinsulcu and hilli are allied species, and are rather 
too dissimilar to the type of Helicarion to be admitted into that 
genus. Much critical examination of the Naninidce of the South 
Seas remains to be done before the genera of that family can be 
suitably defined. The species in question are probably allied to 
the Fijian godeffroyi and to the Papuan hunsteini, I prefer to 
leave them at present under Nanina , using the name in its 
widest significance. 
4. Parmella etheridgei, Brazier , 1889. 
Illustrations. Brazier, Aust. Mus. Mem. 2, pi. 5, fig. 9 (reversed); 
Hedley, Records of the Australian Museum, Vol.i., pi. 1 1 (reversed). 
# Since the above was in type I have learnt from Prof. II. A. Pilsbry, 
of Philadelphia, that he has simultaneously with myself, examined the 
anatomy of N . howinsulcc y and that he has independently arrived at the 
same conclusions regarding its systematic position. Ilis observations 
will probably appear about the time of the issue of this paper. 
