56 PTEROPODA. [Thecosornata. 



Length, 11 mm. 



Hob. Off Great Barrier Island, in 110 fathoms. Atlantic Ocean, 

 Mediterranean, Indian Ocean, and Pacific Ocean. 



5. Cavolina uncinata, Rang, 1836. Plate 6, fig. 5. 



HyalcRa uncinata. Rang, in d'Orbigny, Voy. Amerique uierid., v, 1836 93, 

 pi. 5, f. 11-15. Cavolina uncinata. Gray, Cat. Moll. Brit. Mus., pt. ii, 

 1850, 7 : Pelseneer, Chall. Rep., xxiii, 84. Hyalosa uncinata, Rang and 

 Souleyet, Hist. Nat. Moll.. Pteropodes, 1852, 37, pi. 2, f. 11, 14 ; Conch. 

 Icon., xx. pi. 1, f. 1. H. uncinatiformis, Pfeffer, " Die Pteropoden des 

 Hambnrger Museums." vii. 1880, 85. H. uncinata, Rang : Boas, " Spolia 

 atlantica," 119, pi. 1, f. 10 ; pi. 2. f. 20. 



Shell much swollen ventrally, the surface delicately and regularly 

 reticulated, with fine concentric ridges in front ; dorsal face with 

 3 low, radiating ribs, turned downward and nearly evenly rounded 

 at the aperture ; lateral spines compressed and curved slightly back- 

 ward, central spine rather short, stout, and curved upward. Colour 

 pale amber. 



Length, 9 mm. ; breadth, 6 mm. 



Hob. - - New Zealand. Australia ; Pacific, Indian, and Atlantic 

 Oceans. 



Genus 2. CUVIERINA, Boas, 1886. 



Cuvierina, Boas, "Spolia atlantica," 1886. 131. Type : C. columnella. Rang. 

 Cuvieria, Rang, 1825; not of Peron, 1807. Triptera of authors, not of 

 Quoy and Gaimard. 



Animal with, the aperture of the mantle as large as that of the shell. 

 Posterior portion of the foot slightly hollowed out in its middle region. 



Shell straight, elongated, with a smooth surface, with, ihe posterior 

 half conical and pointed, generally caducous in the adult. The. anterior 

 half is swollen medianly, but constricted behind the aperture. A 

 partition, concave in front, is found towards the middle of the entire 

 length of the shell, and close beside this the truncation is formed. 

 The transverse section is circular, except towards the aperture, where 

 it is a little compressed, and appears somewhat reniform. Behind 

 the aperture the shell is contracted, but bulges out again towards 

 the partition. The embryonic portion is separated from the rest of 

 the shell by a shallow constriction. 



1. Cuvierina columnella, Rang, 1827. Plate 6, fig. 6. 



Cuvieria columnella, Rang, Ann. Sci. Nat. (1), xiii, 323, pi. 45, f. 1-3. / Cleo- 

 dora obtusa, Quoy and Gaimard. 1824. Cuvieria oryza, Benson, 1835. 

 Triptera columnella, Gray. 1850. Cuvieria urceolaris, Moerch. 1850. 

 Triptera columnella and cancellata, Pfeffer. 1879. Cuvierina columnella, 

 Rang : Pelseneer, Chall. Rep. xxiii, 67 ; Hedley, T.N.Z.I., xxxviii, 76. 



This is the only living species, and its characters are those of the 

 genus. 



Length, 14 mm. 



Type (?). 



Hob. Off Great Barrier Island, in 110 fathoms. 



