THE MOLLUSCA HEDLEY. 



485 



HAMINEA VITREA, A. Adams. 

 Pilsbry, loc. tit., p. 370, pi. xl., fig. 83. 

 Two specimens from the lagoon beach. 



The " Chevert " Expedition took this species in Torres Straits. 

 It occurred to me at Panie, New Caledonia ; and under the 

 synonym of H. tenera, A. Adams, Melvill and Standen record 

 it from the Loyalties. 



CYLINDROBULLA SCULPTA, Nevill. 

 Pilsbry, loc. cit., p. 381, pi. xlii., figs. 36 - 38. 



Two living specimens from shallow water in the lagoon, corres- 

 pond fairly to the above quotation. This Cingalese species has 

 not been noticed before in the Pacific. 



AKERA APERTA, sp. nov. 

 (Fig. 47). 



Shell small, fragile, transparent, oval. 

 Whorls two and a half, last sloping on the 

 shoulder, then subangled and rounded 

 below; sculptured by close, regular growth 

 lines. Apex truncate. Spire minute, 

 visible through a flat, glossy plate, which 

 continues into a rib bordering the sutural 

 notch. Aperture as long as the shell, 

 much dilated and effuse below, narrowed 

 above to the broad and deep sinus ; outer 

 lip arched forward above the middle ; 

 columella very concave with a narrow 

 sharply reflexed edge. Length 5, breadth 

 4 mm. 



Three specimens from sand on the 

 lagoon beach. 



This curious shell agrees with Akera in 

 having the spire at the vertex and in the 

 open aperture, but it approaches Cylin- 

 drobulla in the more involute spire. I am 

 not satisfied that this may not be the 

 young of the preceding species, but as no 

 information is published on the immature 

 stages of these genera, it seemed well to 

 describe my material, even at the risk of 

 increasing synonomy. 



HYDATINA AMPLUSTRB, Linne. 

 Pilsbry, loc. cit., p. 390, pi. xliv., figs. 1-6. 

 An immature specimen from the lagoon beach. 



- 47. 



