11 



1. Lithophaga [Lithophaga) teres (Philippi). (Plate II, figs. 38, 39). 



1785. Mylilus lithophagus Chemnitz (ex parte, nec Linn.), Conch.-Cab., VIII, p. 124, 



pi. LXXXII, fig. 729. 

 1846. Modiola teres Philippi, Abbild. Beschreib. Conch., II, p. 148, Modiola, pi. I, fig. 3. 

 1857. Lithodomus teres Reeve, Conch. Icon., X, Lithodoimis, pi. III, fig. 13. 

 1857. Lithopliagus teres Adams, H. & A., Gen. Rec. Moll., II, p. 519. 

 1860. Lithodoimis teres Reeve, Elem. Conch., II, p. 74. 

 1863. ]\Iodiola teres Deshayes, Cat. Moll. Réunion, p. 23. 

 1869. Lithophagus teres Dunker, Cat. Mus. Godeffroy, IV, p. 114. 

 1874. Lithophagus teres Dunker, Cat. Mus. Godeffroy, V, p. 175. 

 1877. Modiola teres Liénard, Cat. Ile Maurice, p. 66. 

 1880. Lithodomus teres von Martens, Môbius Beitràg. Meeresf. Mauritius, Seychell., p. 319. 



1883. Lithophaga teres Dunker in Martini Chemn. Conch.-Cab. (N. F.), VIII (3), Lithophaga, p. 13. 



1884. Lithodomus teres Smith, Rept. Voy. "Alert", p. 109, 



1887. Lithodomus teres von Martens, Journ. Linn. Soc. London (ZooL), XXI, p. 206. 



1888. Dactyliis erythrœensis Jousseaume, Mém. Soc. Zool. France, I, p. 218. 

 1890. Lithodomus teres Paetel, Cat. Conch. Samm., III, p. 206. 



1893. Lithodomus gracilis Dautzenberg (nec Philippi), Bull. Soc. Zool. France, XVIII, p. 84. 



1898. Lithophagus teres Melvill & Standen, Journ. Conch., IX, p. 81. 



1899. Lithophagus teres Melvill & Standen, Journ. Linn. Soc. London (Zool.), XXVII, p. 185. 

 1899. Lithophaga teres Hedley, Mem. Austral. Mus., III, p. 492. 



1905. Lithodomus teres Hidalgo, Cat. Filip., p. 365. 



1906. Lithodomus teres Lamy, Bull. Mus. d'Hist. Nat. Paris, XII, p. 312. 

 1906. Lithophaga teres Hedley, Proc. Linn. Soc. N. S. Wales, XXXI, p. 464. 



1906. Lithophagus gracilis Standen & Leicester (nec Philippi), Ceylon Pearl Oyster Rept., 

 V, 290. 



1909. Lithodomus teres Melvill, Trans. Linn. Soc. London (Zool.) XIII, p. 124. 



1910. Lithophaga teres Hedley, Austral. Ass. Adv. Sci., XII, p. 346. 



191 1. Lithodomus teres Lamy, Bull. Mus. d'Hist. Nat. Paris, XVIII, p. 130. 



191 1. Lithodomus teres Pelseneer, "Siboga" Lamellibranches (Anat.), p. 21, pi. VII, fig. r. 

 1919. Lithodomus teres Lamy, Bull. Mus. d'Hist. Nat. Paris, XXV, p. 252. 



L. (Z.) teres is closely allied to L. gracilis (Philippi) ^), but is distinguished by its much 

 smaller size, much more cylindrical shape and the posterior margin of the valves, which is much 

 less flattened, von Martens ^) and following him Lynge hâve, however, suggested that the two 

 species cannot be separated from one another, while Dunker's ^) suggestion that L. teres is 

 probably only a variety of the West Indian L. niger (d'Orbigny), is, as shown by Lynge, quite 

 untenable. Probably several records of L. gracilis from the Indo-Pacific are really based on 

 spécimens of L. teres. 



Distribution : — L. [L.) teres is widely distributed in the Indo-Pacific. 



In the "Siboga" collection it is represented by shells collected at Macassar (St. 71), 

 Anchorage off Lai Wui, Coast of Obi Major (St. 142), Anchorage off Seget, West entrance of 

 Selee Strait (St. 163) and Anchorage betvveen Gisser and Ceram Laut (St. 172). 



2. Lithophaga {Lithophaga) nasuta (Philippi). (Plate II, figs. 40, 41). 



1846. Modiola nasuta Philippi, Abbild. Beschreib. Conch., II, p. 149, Modiola, pi. I, fig. 2. 

 1857. Lithophaga nasuta Adams, H. & A., Gen. Rec. Moll., II, p. 519. 



i) Philippi, R. A. — Abbild. Beschreib. Conch., III, p. 19, Modiola^ pi. II, fig i (1851). 



2) Martens, E. von. — Môbius Beitrag. Meeresf. Maurilius, Seychell., p. 319 (1$ 



3) Dunker, W. — Op. cit., p. 13 {\\ 



