SACCAMMININAE 329 



test. Surface smooth and without any projecting spicules. Colour, glistening white. 

 Length 1-50 mm.; greatest breadth o-8o mm. 



This very interesting little form, of which only a single perfect specimen was obtained, 

 appears to occupy a position intermediate between T. legiimen Norman and T. melo 

 Norman. It differs from T. legume n in its regularly oval form, and particularly in the 

 absence of that inner layer of sponge spicules set at right angles to the outer layer which 

 marks the high selective and constructional powers of that species, ^ while agreeing with 

 that species in its superficial neatness and the longitudinal arrangement of the spicules 

 in the external wall. It resembles T. melo in its general form and in the construction of 

 its test in a single layer, but differs from that species in its extraordinary neatness. In 

 T. melo the aboral end of the shell bristles with the projecting ends of the spicules, but 

 in our species the aboral end is as neatly finished as the rest of the shell. 



Genus Webbinella, Rhumbler, 1903 



63. Webbinella hemisphaerica (Jones, Parker and Brady) (Plate VIII, fig. 9). 



Webbina hemisphaerica, Jones, Parker and Brady, 1866, etc., MFC, 1866, p. 27, pi. iv, fig. 5. 

 Webbina hemisphaerica, Brady, 1884, FC, p. 350, pi. xli, fig. 11. 

 Webbinella hemisphaerica, Rhumbler, 1903, ZRR, p. 228, fig. 54. 



Two stations: WS 221, 246. 



A single specimen at each station of the original type, characterized by a high-domed, 

 practically semi-globular test without any marginal extension. The specimen from 

 WS 221 is snow white, that from WS 246 of the more usual dark, ferruginous colour. 

 They differ greatly in appearance from the depressed, outspreading type which has 

 sometimes been figured under this name and which we are now separating, being 

 convinced of the absence of any relationship. 



64. Webbinella depressa, sp.n. (Plate VII, figs. 10, 11). 



Webbinella hemisphaerica, Cushman, 1910, etc., FNP, 1910, p. 51, fig. 56; 1918, etc., FAO, 

 1918, p. 62, pi. XXV, figs. 1-3 ; 1922, FHB, p. 6. 



Five stations: WS 93, 221, 225, 245, 246. 



Test sessile, very slightly convex, flattening towards the periphery which is usually 

 more or less irregular in outline, and rarely circular as in W. hemisphaerica. Constructed 

 of very fine sand grains without visible cement and rather thick walled, the central cavity 

 being quite small. Exterior very smooth and neatly finished ; colour varying from nearly 

 white to dark grey, never ferruginous; no visible aperture. Size very variable, ranging 

 from i-o up to 3-0 mm. in diameter. 



Common on shell fragments at WS 246, more rarely at the other stations recorded, 

 and probably widely distributed in the Falkland area, wherever conditions are suitable. 

 Cushman {supra, 1922, FHB) records what is evidently the same form from shallow 

 water in Hudson's Bay under the name W. hemisphaerica, but he draws attention to the 

 many points of difference, and evidently regarded his specimens as a distinct organism. 

 1 H.-A. & E. 1912, etc., NSG, 1912, pp. 382-3, pi. v, fig. i, 2; pi. vi, fig. i. 



