264 Transactions of the Societ/j. 



the type. They are decorated with what appear to be exceedingly 

 fine, short spines, which often seem to coalesce and so give a sugary 

 appearance to the test. I have a fine range of specimens of the 

 type-form from the Seychelles Islands, Mahe Harbour, 14 fms. 

 Some of these attain large dimensions, with only slight lateral 

 compression, and with probably sixteen to eighteen chambers in 

 the final whorl. The lobulation of the rounded peripheral edge is 

 almost lost, and the umbilical region filled up with clear shell- 

 substance, and little decorated. The decoration of the tests con- 

 sists of reticulations. In some cases this decoration is exceedingly 

 fine and beautiful. Small examples are compressed and smoother, 

 and the outline is lobulated. 



Sub-family Ifumraulitinae. 

 Amphistegina d'Orbigny. 



Amjjhistegina lessoni d'Orbigny. 



Amphistegina lessoni d'Orbigny, 1828, Ann. Sci. Nat., vol. vii, p. 304, 



No. 3, pi. xvii, figs. 1-4, Modele No. 98. 

 A. lessoni Brady, 1884, Chall. Eept., p. 740, pi. cxi, figs. 1-7. 



One occurs ; similar to the " Challenger " fig. 2. 



Operculina d'Orbigny. 



Operculina ammonoides d'Orbigny, var. incequilateralis, var. nov. 



(PL VI, figs. 30-34.) 



The type-form is not present, but this interesting variety is 

 well represented. The amount of convexity of the upper surface 

 and the concavity of the under surface varies in the different 

 specimens. In fig. 30 the under surface is almost flat, the septa- 

 tion and aperture being typical. In fig. 33 the edge of the test is 

 sharper, and the septation of the last chambers not so apparent, 

 and the under surface is markedly concave. This latter form, 

 although varying in these particulars, appears to belong to the 

 .same variety. The perforations on the under surface are conspicu- 

 ous in both forms. 



COERIGENDA AND ADDENDA (JoUHl. R. Micr. SoC, 1918). 



Page 20, line 1 from foot, for " irregular " read " circular." 

 ,, 130 ,, 15 from top, for " costuta " read " costata." 

 ,, 136 ,, 21 from top, after " spathulata " add " Sidebottom." 

 ,, 137, after line 19 from foot, add " F. tenera Heron-Allen and Earland, 1916, 



Foram. West of Scotland, Trans. Liuu. Soc. London, vol. xi, pt. 13, 



p. 260." 

 ,, 139, line 5 from top, deZeie " 32 (?) " 

 ,, 141 ,, 19 ,, delete comma and put a hyphen. 



„ 146 ,, 15 ,, for " pygmoea " read "pygmaea." 



-,, 150 ,, 14 ,, for " acquilateralis ■' read " aequilateralis." 



,, 150 ,, 15 ,, Ditto, ditto. 



„ 150 „ 17 „ Ditto, ditto. 



