-86 HALKYARD, Fossil Foraminifera of the Blue Marl 



The species is fairly common at Biarritz. 



(The very extensive and interesting series of both megalo- 

 spheric and microspheric specimens lends considerable value to 

 Halkyard's remarks as to the true nature of Schlumberger's 

 subgenus Amphicoryne, although it is not very evident what 

 the megalospheric form of A. falx can be, assuming his theory 

 to be correct that that species is the microspheric form of some 

 hitherto unconnected species of Marginulina. The only form 

 with which A. falx has any apparent connexion, is Nodosaria 

 scalaris (Batsch) but although we not infrequently find N . sca- 

 laris with Amphicoryne initial portions, they are apparently 

 merely "sports," that is to say microspheric N . scalaris with a 

 tendency to axial curvature. 



The megalospheric and microspheric forms of Marginulina 

 behmi are abundant in the Miocene of Malta, and attain even 

 "better development than in the Biarritz gatherings.) 



195. Marginulina triangularis, d'Orbigny. 



Marginulina triangularis, d'Orbigny, 1846. Foram. Foss. 

 Vienne, p. 71, pi. Ill, figs. 22-23. 



Rather rare and small. This is a species which can be 

 claimed by either of the genera Cristellaria and Marginulina. 



(Halkyard's specimens agree, fairly well with d'Orbigny's 

 figures, but there seems very little reason for separating them 

 from any other of the very various forms of Cristellaria 

 crepidula (F. & M.).) 



Genus Frondicularia, Def ranee. 

 196. Frondicularia complanata, Defrance. 



Frondicularia complanata, Defrance, 1824. Diet. Sci. Nat. vol. 

 XXXII, p. 178, Atlas. Conch, pi. XIV, fig. 4. 



Very rare. Only two imperfect specimens of the elongate 

 form found in the whole of the material examined. 



(Of the two specimens one is flabelline in the initial 

 portion.) 



196A. [Frondicularia spathulata, Brady.] 



[Frondicularia spathulata, Brady, 1879. etc., RRC. 1879, p- 270, 



pi. VIII. fig. 5. 

 Frondicularia spathulata, Brady, 1884, FC. p. 519, pi. LXV. fig. 



18.] 



