197 

 2 8. Tellina {^Peronidid) macassariensis sp. nov. (Plate V, figs. 39, 40). 



This new species is closely allied to T. {P.) cygiitts Hanley ^), but the shell is more 

 trigonal, less elongate, more tumid, less rostrate, but with the beak more oblique and downwardly 

 directed ; the posterior ridge is much better developed and the sculpture consists of very regular, 

 close-set, almost microscopic striae. 



Measurements of Holotype : — Length 12 mm., height 10 mm., diameter 5.5 mm. 



Two shells of this interesting species were collected by the "Siboga" Expédition at Macassar 

 (St. 71, 27 — 32 mètres). 



Genus Macoma Leach. 



18 19. Macoma Leach, Ross, Voy., Appendix II, p. LXII. 



1878. Macoma Bertin, Nouv. Arch. Mus. d'Hist. Nat. Paris, (2) I, p. 333. 



1900. Macoma Dali, Trans. Wagner Free Inst. Sci. Philadelphia, III, p. 1044. 



1900. Macoma Dali, Froc. U. S. Nat. Mus,, XXIII, p. 292. 



1928. Macoma Woodring, Miocène Mollusks from Bowden, Jamaica, Pelecypods etc., p. 176. 



For good définitions of the genus référence may be made to the works of Dall and 

 Woodring cited above. The génotype of Macoma is Macoma tenera Leach (= Tellina calcarea 

 Gmelin). The subgenus Macoma s. s., is not represented in the "Siboga" collection, but there 

 are représentatives of the subgenus Psammacoma Dall '^) — type Macoma [Psammacoma) 



candida (Lam.). 



1. Macoma [Psammacoma) fallax Bertin. 



1846. Tellina candida Hanley (nec Lam.) in Sowerby, Thés. Conch., I, p. 301, pi. LXII, fig. 195. 

 1878. Macoma fallax Bertin, Nouv. Arch. Mus. d'Hist. Nat. Paris, (2) I, p. 343, pi. VIII, 



figs. 4, \a. 

 1909. Tellina [Macoma) fallax Lynge, D. Kgl. Dansk. Vidensk. Selsk. Skr. Nat. Math., (7) 



V, p. 207. 



The "Siboga" spécimens, which I assign to Macoma [Psammacoma) fallax agrée with 

 Bertin's descriptions and figures in ail détails. The largest spécimen in the "Siboga" collection 

 is a right valve 53 mm. long, 31 mm. high. 



Distribution: — Bertin does not indicate the locality of his spécimens, but Hanley's 

 spécimen referred to this species was from the China Seas. Lynge has recorded spécimens from 

 the Gulf of Siam under this name. 



In the "Siboga" collection there is a good séries of spécimens from Madura Strait (St. i, 

 37 mètres; St. 2, 56 mètres), Macassar (St. 71) and Saleyer (St. 213). 



2. Macoma [Psammacoma) arafurensis Smith. 



1885. Tellina [Macoma) arafurensis Smith, "Challenger" Lamellibranchia, p. 98, pi. IV, figs. 6, 6a, b. 



Smith in describing M. [P.) arafiirensis referred to its close relationship with the species 

 from the west coast of Central America described by Hanley under the name Telliîia 



i) Hanley, S. — in Sowerby, Thés. Conch., I, p. 310, pi. LIX, fig. 122 {\\ 



2) Dall, W. H. — Trans. Wagner Free Inst. Sci. Philadelphia, III, p. 1045 UÇOo) and Proc. U. S. Nat. Mus., XXIII, p. 292 (igoo). 



