186 



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 loroad ; formula, 120 rows of 90 : 24 : 1 : 

 24 : 90 ; racliidian 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. HiLLi, Cox, 1873. 



Illustrations. Cox, P.Z.S., 1873, pi. 16, figs. 7a, 7b; Tryon, 

 Man. Conch., ser. 2, Vol. i., pi. 38, figs. 57, 58. 



BescrijJtions. Cox, P.Z.S., 1873, p. 151 ; Pfr., Mon. llel. Viv., 

 Vol. vii., p. 26 ; Tryon, Man. Conch. 2-1-170. 



Type. The Cox Collection. 



Ilab. The summit of Mount Gower. 



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, 1G3 rows of 430:24:1 :24:4:30; 

 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, hoivinsuhe 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 Naninida. 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 huiisteini, I pi-efer to 

 leave them at present under Nani')ia, using the name in its 

 widest significance. 



4. Pakmella 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. H. A. Pilsbry, 

 of Philadelphia, that he has simultaneously with myself, examined the 

 anatomy of N. howinsuloc, and that he has independently arrived at the 

 same conclusions x'egardinjT its systematic position. His observations 

 will probably appear about the time of the issue of this paper. 



