i66 



globosa is the species figfured by Chemnitz and later by Savigny. The shells of the species are, 

 as noted already, not so globose as those of D. bullata and the sculpture is less well developed. 

 The hinge consists of two cardinal teeth in each valve, and of thèse the posterior one is bifid. 



Hedley is wrong in uniting Reeve's Lzicina ovum ^) with D. globosa, as the former, as 

 its hinge shows, is a true Lucina. 



Distribution : — C. globosa is widely distributed in the Indo-Pacific and also occurs in 

 the Red Sea. 



In the "Siboga" collection the species is represented from the Bay of Pidjot, Lombok 

 (St. 33), Bay of Bima (St. 47), Western entrance Samau Strait (St. 59), Muaras Reef (St. 91), 

 Sulu Harbour (Stat. 104) and Lohio Bay, Buton Strait (St. 205). 



3. Diplodonta auriculata Sowerby. 



1905. Diplodonta auriculata Sowerby, Proc. Malacol. Soc. London, VI, p. 281, fig. 2. 



Sowerby in the description of Diplodonta auriculata gave Sierre Leone as its habitat, but 

 the type-shell (N'^ 1905. 10.23.34) in the Collections of the British Muséum (Nat. Hist.), London, 

 is labelled Ceylon, and the same locality is noted in the Receipt Register of the Muséum. 



In the "Siboga" collection there is a single left valve collected on the Bornéo Bank 

 (St. 81), which agrées in every respect with the type shell. 



4. Diplodonta lamyi sp. nov. (Plate V, figs. 21 — 23). 



I associate this new species with the name of my friend Monsieur E. Lamy ofthe Muséum 

 d'Histoire Naturelle, Paris. 



D. lamyi greatly resembles D. jousseaumei Lamy") from West Africa but is distinguished 

 by its much thicker shell, with the anterior margin more rounded, the posterior more rostrate 

 and the ventral margin less arcuate. The umbones are more prominent, and are curved forwards 

 and inwards; the ridge or carina running down from the umbones separating the posterior greatly 

 depressed part of the shell is better developed. The sculpture consists of thin concentric striae. 



Measurements of Holotype (single left valve): — Length 31.5 mm., height 25.5 mm., 

 dianieter 9 mm. 



Habitat : — A number of stray valves of this species were collected in Sapeh Bay, east 

 coast of Sumbawa (St. 311). 



The anatomy of this species was described by Pelseneer as that of Diplodonta subglobosat 



5. Diplodonta dubia sp. nov. (Plate IX, figs. 5 — 8). 



This new species may later hâve to be combined with D. ethima Melvill & Standen ^) 

 but with the material at my disposai, I am of opinion that it is quite distinct. 



The shell of D. diibia is more arched both anteriorly and posteriorly and the ventral 

 margin is less arcuate \ the shell is more tumid and the umbones are more prominent. The 



1) Reeve, L. — Conch. Icou., II, Lucina^ pi. V, fig. 21 (1850). 



2) Lamy, E. — Journ. Conchyliol., LXV, p. 365 (192 1). 



3) Melvill, J. C. & Standen, R. — Journ. Linn. Soc. London (Zool.), XXVII, p. 197, pi. XI, figs. 17, lya (1899). 



