I30 DISCOVERY REPORTS 



D. sutihy is outstanding in the genus owing to its comparatively large size, thick shell 

 wall and elaborate canal system. It is probable that a similar canal system exists in all 

 the species — it certainly does in D. zviesneri — but owing to the thinness of the wall of the 

 test in the three Mediterranean species figured by Sidebottom (Nos. 262-4) it will 

 be difficult to demonstrate its existence. 



266. Delosina wiesneri, sp.n. (Plate V, figs. 915). 



Delosina complexa, "broad form", Wiesner {non Sidebottom), 1931, FDSE, p. 123, pi. xxi, 

 figs. 255-6. 



Three stations: 170, 363; WS 482. 



Test hyaline, thick-walled and finely perforate; subglobular in the megalospheric 

 form, the megalosphere being prominent, though smaller than in D. sutilis. In the 

 microspheric form the dorsal side rises in a steep cone to a blunt point. In both forms 

 the ventral side is flattened. Chambers up to 8-10 in number, arranged triserially, 

 sometimes biserial in the final convolution ; inflated, increasing rapidly in size and nearly 

 enveloping the early growth ; all chambers visible on dorsal side, those of the last con- 

 volution only on the ventral side. Sutures nearly flush, marginal edge of each chamber 

 overlapping its predecessor as in D. sutilis. The canal and its branches or " stitches " are 

 visible only on the ventral side of the Discovery specimens, but can be temporarily 

 demonstrated elsewhere by immersing the specimen in fluid. In the specimens from 

 the ' Gauss ', which are larger and more varied in build, both the canal and the " stitches " 

 can be seen on other parts of the test, but they are less conspicuous than in D. sutilis. 

 There does not appear to be any sieve-like area on the terminal face as in D. sutilis, but 

 there are occasional larger punctae scattered over the surface of the chambers in some 

 of the Gauss specimens, which may be homologous. The test is smooth but less highly 

 polished than in D. sutilis, and the colour is less pronounced. 



Height of megalospheric form about 0-45 mm. ; of microspheric about 0-6 mm. ; breadth 

 of megalospheric varies between o-40-o-55 mm.; of microspheric about 0-55 mm. 



D. wiesneri is very rare in the Discovery material compared with D. sutilis; in the 

 Gauss material conditions are reversed. Two specimens were found at St. 363 in the 

 South Sandwich Islands, and two at St. 170, Clarence Island; a single specimen only 

 at St. WS 482. 



Genus Virgulina, d'Orbigny, 1826 



267. Virgulina squammosa, d'Orbigny. 



Virgulina squammosa, d'Orbigny, 1826, TMC, p. 267, No. i ; Modele No. 64. 

 Virgulina squamosa, Brady, 1884, FC, p. 415. 



Virgulina squammosa, Cushman, 1925, etc., LFR, 1932, p. 15, pi. iii, fig. i. 

 Virgulina squamosa, Macfadyen, 1931, MES, p. 56, pi. i, fig. 23. 



Seven stations: 167, 194, 196; Port Lockroy ; WS 476, 482, 486. 



Very rare everywhere except at St. 167, where it is not uncommon. The specimens 

 are small and not very satisfactory. 



^ suttlts= stitched together. 



