F()i:amtntfrka-heron-allen and earland. 2on 



infliule every eonceivable monstrosity, and a number of .specimens ,simulatin<f tlie 

 strueture of widely-separated genera. Many individuals with regularly textularian 

 eliaml)ers, others proceeding from textularian to bigenerinc, others with acervuline 

 masses. At Stations 2 and 3, in addition to the type (_)f usual truncatulinc 

 texture, a form occurs abundantly, both sessile and attached, in wliicli the shell- 

 wall is very finely tubulate, thick and glistening. This type does not occur else- 

 where in the gatherings. 



[Arenaceous isomoi-ph, Ildjiloji/iniijuniini aninriciisc, var. varidhiUs, II. -A. & E.] 



553. T nuicatuUna icnui)nargo, Brady. 



Truiicatulina tenuiman/o, Brady, 1884, FC. p. 602, pi. XL-iii, figs. 2, .3. 



„ „ HiTon-Alk'ii and Farlaiid. 11)11, etc., FKA. ilJl.'j, p. 707. 



Stations 2, 3, (3. 8. 12. 



A few typical specimens of the Iceeled type represented by Brady's fig. 3 

 occur. I^'ossil specimens at Stations 2, 3, and (3. 



554. Truncatulina tenuimargo, var. alto-camemtu, nov. PL VII, fig. 24-27. 



Tniiiai/iiliiiii IciuniiiKiyo, Brady, 1884, FC. p. 662, pi. xciii, fig. 2. 



Sidoi)ottom, 1918, FECA. p. 257. pi. vi, lig.s. 20, 21. 



Stations 2, 3, G, 7, 11, 12. 



The extraordinary variety achuubratcd li\- Erad\- in Jiis Fig. 2, and figured 

 by Sidebottom {ut supra) occurs generally over the N.Z. area, though specimens, 

 are rare. Braily's figure represents a transition form between carinate T. lobatulu 

 and the high conical-chambered Sidebottom figiu-e, and such intermediate speci- 

 mens, representing all stages of transition, occur at Stations 3 and (i. The 

 variety reaches its nuiximum development at Station 2. with individuals having 

 as many as eight high conical chambers to the whorl. At Station 6. where it 

 was most frequent, the specimens are much smaller and the cone is less elevated. 

 Beyond Station G it gradually dies out, becoming very rare and smaller in the 

 deeper water, and at Station 12 the cone is hardly more prominent than in 

 Brady's figure. All the specimens at Station 7 were dead and discoloured shells. 

 At Station 3 an individual, intermediate between the extreme types, occurs with 

 pustules of solid shell-matter on the low cones of the chambers. Fossil and 

 recent at Stations 3 and (3 ; the fossil specimens and the recent are identical. 

 Seguenza figures and describes a form as Discorbina plano-convexa, having some- 

 what similar characteristics, but referable l)y its aperture to Discorbina, and it 

 may be regarded as an isomorph (S. 1882, C'MIM. p. 199, pi. xxi, fig. 2a, b). 

 A somewhat similar form is described and figured by Schwager (S. 1883, ELW. 

 p. 126, pi. xxix, fig. 14) under the name Truncatulina colliyera, but the chambers 

 are less dome-shaped and prominent. , 



The size varies greatly, attaining a length of •70 mm. and a breadth of 

 ■50 mm., with a maxiinum height of •30 mm. in the final chamber. 



VOL. VI. 2 E 



