FORAMINIFERA— HERON-ALLEN AND EARLAND. 109 



the individuals are constructed of large angular sand-grains, cemented with, 

 ferruginous cement, and usually so embedded as to present a relatively, smooth 

 contour, although in many specimens single isolated grains of larger size than 

 usual project. The aperture is situated at the end of a produced neck con- 

 structed of very fine sand-grains with a maximum of cement, but owing to its 

 fragility is often wanting, though its traces can always be fomid upon examina- 

 tion. There can be no doubt that Pearcey's Reophax robustus is referable to this 

 species (P. 1914, SNA, p. 1006, pi. i, figs. 6-10), indeed, his figures represent the 

 megalospheric and microspheric forms, and the produced neck, perfectly. It 

 appears not improbable that Cushmans R. advena represents a closely-allied 

 species, described from specimens in which the produced neck is lacking. 



AMMODISCUS, Reuss. 



154. Ammodiscus incertus (d'Orbigny). 



Operculina incerta, d'Orbigny, 1839, FC. p. 49, pi. vi, figs, 16, 17. 

 Ammodiscus incertus, Cushman, 1910, etc., FNP. 1910, p. 73, fig. 95, 



Stations 2, 6, 7, 26-29, 33, 40, 41, 47, 53, 55 {+ D,). 



All the specimens are small except at Station 2 (N.Z.), where they are 

 gigantic. Attached specimens at Station 6. At Station 29 the species is common 

 and characterized by extremely neat, many-coiled individuals built with a maxi- 

 mum of cement. At Station 53, the largest Antarctic individual represents the 

 species and is abnormal in the presence of a wild outgrowth on the last convolu- 

 tion. 



[Porcellanous isomorph Cornuspira involvens, Rss. ; Hyaline isomorph, Spiril- 

 lina vivipara, Ehbg., closely-coiled forms. Cf. Spirillina arenacea in W. 1858, 

 RFGB. p. 93,] 



155. Ammodiscus tenuis, Brady. 



Ammodiscus tenuis, Brady, 1879, etc., RRC. 1881, p. .51 ; 188-t, FC. p. 332, pi. xxxviii, figs. 4-6. 

 incertus (pars), Cushman, 1910, etc., FNP. 1910, p. 75, fig. 96. 



Stations 2, 5, 6, 29. 



A few specimens only. The best N.Z. individuals, very large, at Station 6. 

 One Antarctic specimen at Station 29. 



[Porcellanous isomorph, Cornuspira foUacea (Phil.). Hyaline isomorph, Spirillina 

 vivipara, Ehbg., e volute forms.] 



156. Ammodiscus mestayeri, Cushman. 



Ammodiscus mestayeri, Cushman, 1919, RFNZ. p. 597, pi. Ixxiv, figs. 1, 2. 



Stations 2, 5, 6. 



As noted by Cushman, this form appears to be confined to the N.Z. area. It 

 attains a very large size at Stations 2, 5, 6, especially at the last. Both the 



