285 



igoo. Corculum cardissa Dali, Proc. U. S. Nat. Mus., XXII, p. 385. 



1903. Heniicardiinn cardissa Hidalgo, Obras Malacol., II, p. 359. 



1905. Hemicardium cardissa Hidalgo, Cat. Filip., p. 346. 



1906. Hemicardium cardissa Owston, Japan. Loochooan Shells, p. 40. 



1911. Hemicarditmi cardissa Pelseneer, "Siboga" Lamellibranches (Anat.), pp. 55, 56, 57, 



pi. XX, fig. 8. 

 1928. Cardium {Hemicardiinn) cardissa Faustino, Summary Philippine Mar. Freshw. Moll., p. 63. 



I agrée with Romer (loc. cit., p. 115) that it is possible to separate Corculum cardissa 

 from C. inonstrosiLvi but the différences are not sufficiently marked to consider the two as 

 separate species. 



The typical C. cardissa is comparatively much more depressed and has a distinctly spiny 

 keel, while in var. inonstrosum the anterior, prae-umbonal région is much more convex and greatly 

 raised, while the post-umbonal région is distinctly concave; the keels are also markedly curved 

 and almost smooth. I figure shells of the two forms. 



Distribution : — C. cardissa is very widely distributed in the Indo-Pacific. 



In the "Siboga" Expédition there is a single shell of this species collected in Sanana Bay, 

 East coast of Sula Besi (St. 193). 



2. CorciLhim cardissa var. vwnstrostcm (Gmelin). (Plate VI, figs. 35, 36). 



1742. Cordi-forme naviculiforme D'Argenville, Hist. Nat., pp. 332, 335, pi. XXVI, fig. D. 



1782. Cardium inonstrosum Chemnitz, Conch.-Cab., VI, p. 155, pi. XIV, figs. 149, 150. 



1788. Cardium monstrosnm Schroter, Conch. Cab. Namen Reg., p. 19. 



1789. Cardium cardissa var. D Bruguière, Encyclopéd. Méthod., I, p. 209. 



1790. Cardium monstrosum Gmelin, Syst. Nat., (éd. XIII), p. 3253. 



1797. Bruguière, Encyclopéd. Méthod., pi. CCXCV, figs. \a, b. 



1798. Corculum dolorosum Roding, Mus. Boltenianum, p. 189. 

 18 17. Cardium monstrosum Dillwyn, Descr. Cat., I, p. 112. 



18 19. Cardium iuversum Lamarck, Anim. sans Vertèb., VI, p. 16. 



1824. Cardium iuversum Dubois, Epitome, p. JJ. 



1825, Cardium inversum- Sowerby, Cat. Tankerville, p. 17. 



1835. Cardium iuversum Deshayes in Lamarck, Anim. sans Vertèb., VII, p. 412. 



1841. Cardium iuversum Sowerby, Conch. Illustr., p. 7. 



1843. Cardium Monstrosum Hanley, Rec. Biv. Shells, p. 143, pi. XVII, fig. 32. 



1844. Cardium cardissa Reeve (non Linn., ex parte), Conch. Icon., II, Cardium, pi. III, 



figs. 15«, b, c, f. 



1845. Cardium m.onstrosum Catlow & Reeve, Conch. Nomencl., p. 43. 

 1855. Hemicardium inversum Berge, Conchylienbuch, p. 65. 



1857. Hemicardia monstrosa Adams, H. & A., Gen. Rec. Moll., II, p. 458. 

 1862. Hemicardium- inversum Chenu, Man. Conchyliol., II, p. iil, fig. 517. 

 1869. Cardium [Corculum) monstrosum Rômer in Martini-Chemn., Conch. Cab. (N. F.), X (2), 



Cardiacea, p. 117, pi. VI, figs. 7, 8. 

 1872. Hemicardia monstrosa Tryon, Amer. Journ. Conch., VII, p. 270. 

 1890. Hemicardium [Hemicardium) monstrosum Paetel, Cat. Conch. Samm., III, p. 119. 

 1903. Hemicardium monstrosum Hidalgo, Obras Malacol., II, p. 362. 

 1905. Hemicardium monstrosum Hidalgo, Cat. Filip., p. 347. 



191 1. Hemicardium monstrosum Pelseneer, "Siboga" Lamellibranches (Anat.), p. 55. 

 1928. Cardium [Hemicardium) monstrosum Faustino, Summary Philippine Mar. Freshw. Moll., p. 64. 



The main distinguishing characters of this variety from the typical C. cardissa hâve been 

 .noted already [antea p. 285). 



