Order SEPTIBRANCHIA. 



Family Poromyacidae. 



Genus Poromya Forbes. 



1844. Poromya Forbes, Rept. MoU. Aegean Sea, p. 143. 



1846. Embla Lovén, Ind. Moll. Scand., p. 46. 



1847. Embla Gray, Proc. Zool. Soc. London, p. 193. 



1856. Thetis Adams, H. & A., Gen. Rec. Moll., II, p. 167. 



1886. Poromya Dali, Bull. Mus. Comp. Zool. Harvard, XII, p. 280. 



1887. Poromya Fischer, P., Man. Conchyliol., p. 1172. 



1903. Poromya Dali, Trans. Wagner Free Inst. Sci. Philadelphia, III, p. 1508. 



1925. Poromya Woodring, Miocène Mollusks from Bovvden, Jamaica, Pelecypods etc., p. 88. 



For a good description of the genus Poromya référence may be made to Dall and 

 Woodring. The génotype is Poromya anatinoides Forbes = P . graniilata (Nyst). 



In the "Siboga" collection the genus is represented by Poromya s. s., and Cetoconcha 

 Dall ^) — type Poromya {Cetoconcha^ bulla (Dall). 



1. Poromya [Poromya^ pergranosa sp. nov. (Plate VII, figs. 27, 28). 



Poromya [Poromya^ pergranosa is closely allied to P. i^P.) australis Smith ^) but the 

 shell of the new species is comparatively longer, more elongate-ovoid, with the posterior margin 

 distinctly truncate and ventral border less arcuate. The shell is less tumid, but the umbones 

 are a trifle more prominent and there is a well marked radial ridge running from the umbones 

 to the ventral border and separating a slightly concave posterior area of the valves. The 

 sculpture is quite similar to that of P . {P.) atistralis. The shell is thicker and is of a light 

 yellow ochre tint \ the nacre is pearly white. 



Measurements of Holotype : — Length 5.9 mm., height 5 mm., diameter 3.6 mm. 



Habitat: — The unique Holotype was dredged at St. 154 (o°7'.2N., i30°25'.5E., 

 83 mètres). A stray right valve dredged with the above is somewhat larger, but appears to 

 belong to the same species. 



2. Poromya {Cetoconcha) gloriosa sp. nov. (Plate VII, figs. 29, 30). 



The foUowing is a description of this new species : — Species of a moderate size ; shell 

 elongate ovate, subequilateral, inequivalve, rostrate, thin ; moderately inflated, compressed in 



i) Dall, W. H. — Bull. Mus. Comp. Zool. Harvard, XII, p. 280 (1886). 



2) Smith, E. A. — "Challenger" Lamellibranchia, p. 54, pi. XI, figs. 2, 2a^b (1885). 



