317 



1898. Xylophaga Dali, Trans. Wagner Free Inst. Sci. Philadelphia, III, p. 821. 

 1903. Xylophaga Smith, Proc. Malacol. Soc. London, V, p. 328. 



1925. Xylophaga Woodring, Miocène Mollusks from Bowden, Jamaica, Pelecypods etc., p. 195. 



1926. Xylophaga Lamy, Journ. Conchyliol., LXIX, p. 98. 



A detailed description of the genus Xylophaga is to be found in Lamy's work cited 

 above. The génotype is Xylophaga dor salis Turton. 



I. Xylophaga tomlini sp. nov. (Plate VII, figs. 9, 10). 



Xylophaga tomlini is closely allied to X. praestans Smith ^), but the new species has a 

 comparatively much smaller and thinner shell. The sculpture of its anterior triangular plate 

 differs from that of X. praestans in the much larger number of closely situated, parallel, raised 

 lines, the absence of the "lunule-like space", the more strongly developed keel and the much 

 more incurved umbones. The protoplaxes or the dorsal accessory plates are missing. The internai 

 rib is well developed, but is not so strong as in X. praestans. The shells are of a dirty 

 yellowish-white colour. 



Measurements of Holotype : — Length 16 mm., height 15 mm., diameter 14 mm. 



Habitat : — A single shell of this new species was brought up in a deep-sea trawl at 

 St. 88 (o°34'.6N, ii8°53'E., 1301 mètres). 



Remarks : — Unfortunately the available material of this new species, which I hâve 

 named after my friend Mr. J. R. le B. Tomlin, is very limited, but after a careful comparison 

 with the other known species of the genus, I hâve no doubt that the "Siboga" shell belongs 

 to an undescribed species. 



Genus Pholadidea Goodall. 



18 19, Pholadidea Goodall in Turton, Conch. Dict., p. 147. 



In the "Siboga" collection there is a single shell of the genus Pholadidea^ which I cannot 

 identify with any known species, but which owing to the unsatisfactory nature of the spécimen 

 I am not able to describe as a new species. This spécimen was brought up in a trawl at St. 306 

 (8° 27' S., i22°54'.5E., 247 mètres). 



Genus Martesia Blainville. 



1825, Martesia Blainville, Man. Malacol., p. 632. 



1856. Martesia Adams, H. & A., Gen. Rec. MolL, II, p. 330. 



1887. Martesia Fischer, P., Man. Conchyliol,, p. 1136. 



iZ^yè.^ Martesia Dali, Trans. Wagner Free Inst, Sci. Philadelphia, III, p. 819, 



1925. Martesia Woodring, Miocène Mollusks from Bowden, Jamaica, Pelecypods, etc., p. 194. 



1930. Martesia Stewart, Spécial Publication Acad. Nat, Sci. Philadelphia, N° 3, p. 294, 



Woodring's work may be consulted for a good définition of the genus Martesia, while 

 Stewart has fully discussed the identity of the génotype Martesia striata (Linn.). 



In the "Siboga" collection the genus Martesia is represented by a single left valve, 

 which I hâve identified as M. niultistriata (Sowerby). 



i) Smith, E. A. — Proc. Malacol. Soc. London, V, p. 328 (1903). 



