KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. wN:o [6. 
bo 
or 
FAM, GALEOMMATIDAE, 
Ephippodonta granulifera n. sp. (Pl. 1, fig. 20, text figs. 3, 4). Mussle with 
the valves widely gaping, elliptic in outline seen from above, its breadth being more 
than half its length. Valves elongated ovate, convex, with the dorsal margin straight, 
anterior and posterior margins rather abruptly set off from the dorsal margin, and 
forming a rounded corner with the inferior margin, the latter only feebly convex. 
Umbones somewhat in front of the middle. Median part of the shell strongly in- 
flated, towards each end passing into a strong depression. Sculpture (fig. 4) consists 
of extremely fine and dense radiating dichotomically branching costae, set with very 
minute and dense granulae in a concentric arrangement all over the valve. Colour 
Fig. 3. Ephippodonta granulifera n. sp. Animal Fig. 4. Shell seulpture of Ephippodonta 
from under side; left valve and mantle half re- granulifera n. sp. X 40. 
moved. b. gills, f- foot with byssus; g. genital 
organs, @. inner brim of mantle; J. labial palps; 
s. branchial sipho. 
snowy. Dimensions of the valves: |. 1l.6; h. 5.4; breadth of the mussle 7 mm. 
Mantle minutely papillated exteriorly and covering the valves, except for a nar- 
row median stripe across each valve. 
Inferior side of the mussle (fig. 3) shows a wide and thickened expansion of 
the mantle, filling the gap between the valves, but leaving for the foot a median 
split, which stretches from the second third to the hinder end; mantle edges with 
a densely tentaculated brim. Locality: 45 miles W. 8. W., 72 feet (1/7), 1 sp. 
This new and interesting form differs from EH. macdougalli established by Tatr 
(1889) and later on described in greater detail by Woopwarp (1898), in its granular 
surface and the imperfect reflection of the mantle over the shell. The nearly equal- 
sized EH. macdougalli, max. 11 mm (Woopwarp) has spiny valves, which are entirely 
covered by the mantle. 
K. Sv. Vet. Akad. Hand]. Band 52. N:o 16. 4 
