96 DE. T. DAVIDSON ON EECENT BEACHIOPODA. 



aleutica. T. frontalis has never been found at the Shumagin Islands, where M. ctleutica 

 abounds. Still all that can be said is hardly decisive, and must be left to individual 

 judgment to be weighed, and future collectors to prove either way." Mr. Dall observes, in 

 his description of the shell, that " the animal is rather sluggish, and living specimens 

 kept in sea-water for several days exhibit no further signs of life than the slight opening 

 of the valves. The soft parts are of a darker reddish colour, and show through the shell 

 to some extent, as in Waldheimia venosa. There is some variation in form, some speci- 

 mens being much broader than others." 



52. Magasblla Adamsi, Davidson. (Plate XVII. figs. 18, 19.) 



Magasella Adamsi, Davidson, Proc. Zool. Soc. p. 307, pi. xxx. figs. 2.3, 24, 1871 ; Dall, Proc. Acad. 

 Nat. Sci. Philadelphia, 1873, p. 188 ; G. Dunker, Index Mollusc, maris Japonici, p. 253, 1882. 



Shell smaU, nearly circular, as broad as long. Dorsal valve slightly convex, and 

 marked with about eleven more or less prominent ribs, of which the ventral one, in the 

 dorsal valve, is both the largest and the most elevated. Ventral valve deeper than the 

 dorsal one, with about twelve ribs, of which the central ones are both the largest and 

 most prominent, leaving a rather deep median sulcus between them ; beak truncated 

 by a rather large incomplete foramen ; deltidium-plates small ; shell-punctures large and 

 prominent. In the interior of the dorsal valve the loop is doubly attached, first to the 

 base of the hinge-plate and then to a large prominent septum, extending from under 

 the umbonal beak to about half the length of the valve. Colour white. Length 

 9 lines, width 2, depth 1 line. 



Sab. Two examples only of this small species were dredged by Mr. A. Adams, in 26 

 fathoms, in the Sea of Japan, off the island of Kuro-puna. 



Obs. In one specimen the ribs were almost obsolete. We know, however, far too little 

 about this shell to be able to speak in a decided manner with respect to its specific 

 value. In external appearance it differs from all the known recent forms with which I 

 am acquainted. 



53. Magasella Gouldi, Dall. (Plate XVII. figs. 20-22.) 



Mayusella Gouldi, Dall, MS. in Davidson, Japanese Brachiopoda, Proc. Zool. Soc. 1871, p. 307, 

 pi. xxxi. fig. 11 a,b,c; Dall, Amer. Journ. of Couchology, vol. vii. p. 67, pi. xi. fig. 11, 1871, and 

 Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 189 ; G. Dunker, Index Mollusc, maris Japonici, p. 253, 

 1882. 



Shell very small, transversely oval, wider than long ; hinge-line nearly as long as the 

 breadth of the shell ; beak somewhat produced and slightly incurved, with a large 

 incomplete horseshoe-shaped foramen ; deltidial plates very small and widely separated ; 

 false area flattened. Ventral valve deep ; dorsal valve slightly convex, with a shallow 

 longitudinal mesial depression or groove beginning at half the length of the valve 

 and extending to the front surface of each valve ; marked with about eighteen ribs, 

 of these, two median ones lie in a kind of sulcus in each valve and extend from the 

 umbo to the front, while the others are both irregular in width, stouter, and do not 

 extend to more than half the length of the valve from the margin. The lines of growth 



