34 HALKYARD, Fossil Foraminifera of the Blue Marl 



60. Textularia biarritzensis, sp. nov. 

 PL II, fig. 6. 



Test free, elongate, rectangular with rounded corners in 

 transverse section, laterally compressed in the opposite direc- 

 tion to that usual with Textularia. Aboral extremity obtusely 

 pointed. .Sutures very slightly excavated, Chambers margined 

 with a clear shell deposit. Texture smooth. Length, .45 mm. 



This small form is very rare, only one specimen being 

 found at Biarritz. The colour of this single specimen is yellow- 

 ish brown, being to all appearance stained with iron oxide. 

 The degree of depression is such as to make the side of the 

 test on which both series of chambers can be seen only one 

 half the width of that side showing the orifice and one series 

 of chambers only. The aboral portion of the shell is faintly 

 striate, and the sutures are occasionally faintly pitted. 



In 1895, A. Rzehak figured a somewhat similar variety 

 under the name of P s eudote xtularia varians*. My shell differs 

 from the above-named chiefly in being more square in trans- 

 verse section, more obtuse at the aboral end, and less tapering 

 in outline as viewed from the biserial side. It will be seen 

 from the figure here given that, as regards the. last characteristic 

 mentioned, my specimen tapers towards both ends of the test. 



(The colour and general appearance of the specimen 

 suggests a derived fossil of cretaceous origin, and this also 

 appears to have been Halkyard's view, as a note among his 

 MSS. states that "it may possibly be a derived fossil from the 

 underlying cretaceous beds, as its colour, rather iron stained 

 and general state of preservation is somewhat different from 

 the other Foraminifera found in the Biarritz Marl." Rzehak's 

 figure referred to by Halkyard has only a limited resemblance 

 to the specimen. Halkyard's specimen apoears to have more 

 points of identity with d'Orbigny's little known genus Cuneolina 

 with whch we have dealt elsewhere, and which was of cre- 

 taceous derivation. (Heron-Allen, J. R. Micr. Soc. 1917, 

 p. yy.) The curious variety of Textularia trochus figured 

 by Goes (G. 1882, R.R.C.S. p. 80, pi. V, figs. 167-170) is also 

 very nearly allied to Halkyard's type.) 



Genus Bigenerina, d'Orbigny. 



61. Bigenerina pennatula (Batsch). 



Nautilus (Orthoceras) pennatula, Batsch, 1791, Conch. 

 Seesandes, pi. IV, figs. I3a-i3c. 



* Ann. K. K. Naturhist. Hofmus. Wien, 1895, Band X. (2) p. 217, pi. VII, 

 figs. 1-3. 



