69-4 Transactions of the Society. 



Spirillina limbata Brady. 



Spirillina limbata Brady, 1879, Quart. Journ. Micr. Sci., n.s., 

 vol. xix. p. 278, pi. viii. fig. 26. S. limbata (Brady) Egger, 1893, 

 Abhandl. k. bayer. Akad. Wiss., CI. II. vol. xviii. p. 395, pi. xviii. 

 figs. 43, 44. S. limbata (Brady) Flint, 1899, Eep. U.S. Nat. Mus. 

 for 1897 (1899), p. 326, pi. lxxi. fig. 5. 



S. limbata — as represented by the form having a square peri- 

 phery, and the faces plane, with limbate sutures, but without 

 tubercles — is rare and poor in the Malay Archipelago, and has been 

 noted only at Stations No. 2 and No. 22. 



Brady names thirteen localities for the species, widely apart ; 

 Egger records it from four ' Gazelle ' Stations ; and Siddall has 

 found it in the Estuary of the Dee. The ' Albatross ' Station from 

 which Flint procured it has not been recorded. 



Spirillina limbata var. denticulata Brady. 



Spirillina limbata var. denticulata Brady, 1884, Chall. Kept., 

 p. 632, pi. lxxxv. fig. 17. S. limbata denticulata (Brady) Egger, 

 1893, Abhandl. k. bayer. Akad. Wiss., CI. II. vol. xviii. p. 396, 

 pi. xviii. fig. 66. 



This variety also is very rare, and has been found only in the 

 material from Station 17. 



The Stations recorded by Brady are : East Moncceur Island, 

 Bass Strait, 38 fathoms ; Eaine Island, Torres Strait, 155 fathoms ; 

 and Nares Harbour, Admiralty Islands, 17 fathoms. The solitary 

 ' Gazelle ' Station is at Kerguelen, 57 fathoms. 



In the Tertiary beds of St. Erth, Cornwall, a modification of 

 this variety occurs ; in which, whilst one face is in all respects 

 similar to those of denticulata, the other is covered with tubercules, 

 and the suture is not apparent. 



Spirillina margaritifera Williamson var. semiornata var. n., 



plate VII. fig. 3. 



Test, inequilateral ; convolutions, numerous ; peripheral edge, 

 square. One of the lateral faces flat and smooth, with the spiral 

 suture excavated ; the opposite face concave, and ornamented with 

 a single row of tubercles arranged closely together in a spiral line 

 Diameter • 60 mm. 



Williamson's knowledge of Spirillina margaritifera was de- 

 rived from a single specimen from an unknown locality, and, as 

 he justly states, " any species founded on a single specimen can 



