1871.] MR. T. DAVIDSON ON JAPANESE BRACHIOPODA. 307 



rounded at the front, but when full-grown is nearly straight, or even 

 sometimes slightly sinuated at the frontal margin. The different 

 variations I have observed in this shell are figured in Plate XXX. 

 The foramen is small, and with age becomes gradually more distant 

 from the hinge-line by the development of the deltidium plates. The 

 surface is smooth. In colour it varies considerably : some specimens 

 are ashy white ; others have a general salmon-colour, which deepens 

 into orange-red near the lines of growth or margins of the shell. 

 In some examples, besides a general reddish tint, a few ruddy rays 

 mark the lateral portions of the shell, but rarely so strongly defined 

 as in Sowerby's figure, in which the coloration is exaggerated. 



Hab. Sowerby states that his specimen of T. rubella was obtained 

 from Japan. Mr. A. Adams dredged it from a clear stony bottom 

 off the pretty little island of Kuro-Sima, at a depth of 35 fathoms. 

 Prof. R. Plumpelly gives as its habitat the wharf at Yokohama, Japan 

 {Ball). 



Subgenus Magasella, Dall. 



This subgenus would comprise the following recent species : — M. 

 evansi, Dav. ; M. crenulata, Sow. ; M. inconspicua, Sow. (accord- 

 ing to Dall) ; M. flexuosa, King ; M. (Ter.) svffusa, Reeve (of this 

 species I possess the original specimen, and can assert that it pos- 

 sesses the elevated septum and loop of Magasella) ; M. Icevis, Dall ; 

 M. (T.) Cumingii, Dav. 1 ; and the following two new Japanese 

 species : — 



Magasella adamsi, Dav. (Plate XXX. figs. 23, 24.) 



Shell small, nearly circular, as broad as long ; dorsal valve slightly 

 convex, and marked with about eleven more or less prominent ribs, 

 of which the central one, in the dorsal valve, is both the largest and 

 most elevated. Ventral valve deeper than the opposite one, with 

 about twelve ribs, of which the two central ones are both the largest 

 and most prominent, leaving a deepish median sulcus between them ; 

 beak truncated by a rather large incomplete foramen • deltidium- 

 plates small ; shell-punctures large and prominent ; colour white. 

 In the interior of the dorsal valve there exists a Mag asel la-shaped 

 prominent septum, extending from under the umbonal beak to about 

 half the length of the valve, and to the lateral sides of it are attached 

 the principal pair of lamellae prior to becoming reflected. Length 2, 

 width 2, depth 1 line. 



Hab. Two examples of this small species were dredged by Mr. A. 

 Adams in 26 fathoms water in the sea of Japan, off the island of 

 Kuro-puna. In some specimens the ribs are almost obsolete. 



Magasella gouldi, Dall, MS. (Plate XXXI. fig. 11, a, b, c.) 



Shell 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 ; 

 deltidium-plates very small and widely separated ; false area flattened. 

 Ventral valve deep ; dorsal valve slightly convex. Surface of each 



