FORAMINTFERA— HERON-ALLEN AND EARLAND. 163 



365. Lagena orbignyana, var. coronata, Sidebottom. 



Lagena orhi/jnijana, var. coronata, Sidebottom, 1912, etc., LSP. 1912, p. 41G, pi. xix, fig. 15. 



Cushmaii, 1910, etc., ENP. 1913, p. 43, pi. xx, fig. 3. 



Stations 16, 17, 36. 



Confined to deep-water Stations. Frequent and typical at Station 16. At 

 Station 36 the variety is represented by a single very fine individual, in which, 

 the carinae are interrupted in the middle of the base, and replaced by a tuft 

 of fine spines. 



366. Lagena orbignyana, var. unicostata, Sidebottom. 



Lagena orbignyana, var. unicostata, Sidebottom, 1912, etc., LSP. 1912, p. 417, pi. xix, fig. 22. 



Stations 17. 29. 



A number of specimens with very variable minor features can, perhaps, be 

 best referred to this vaiiety. The basal notch in the carina indicated in Side- 

 bottom's figure is generally extremely strong ; in fact, all three keels are thus 

 cut away in some specimens at the actual base of the shell. The central costa 

 which gives it the varietal name is represented in different specimens by one, 

 two. or three bars. Occasionally it is reduced almost to the clear bead of var. 

 tvallenana. indicating a transition stage between many forms of the orbignyana 

 type. 



367. Lagena orbignyana, var. yohoyamae, Millett. PL VI, figs. 17, 18. 



Lagena yokoyamae, Millett, 188-5, etc., St. E. 1894, p. 657 (no fig.). 



Stations 1-3, 6. 



Differmg from the normal L. orbignyana in the thick, ill-developed median 

 carina, in the development on the surfaces of the shell, of a series of ridges extending 

 from the margin of the clear convex faces to the inner siuface of the raised 

 outer carinae. The marginal fringe of the chamber is by this means cut up into 

 a series of radiating depressed chamberlets, which, in the majority of specimens, 

 take the form of sunken pits separated by narrow high ridges. At Station 3, 

 however, a number of specimens show these radial chamberlets to be covered 

 with a superficial enclosing wall continuous with the outer test of the chamber, 

 so that each becomes a sealed cavity, and this may be, possibly is, the normal 

 type, the enclosing surface-membrane being sufficiently thin to become easily 

 absorbed or destroyed during the life-time of the animal, and so forming the 

 sunken " trenches " or pits. 



Dimensions: — Length, •30--35mm. ; breadth, -22- -23 mm. 



This very striking form is confined to the N.Z. area, where it is comparatively 

 frecpient at Stations 2 and 3. 



These specimens appear to be closely allied to, if not identical with, the 



Y 2 



