RADIOLARIAN. 371 



body; and, according to the measurements there given of the two magnified 

 aspects of this little fossil, fig. 23 a X 50 gives O'-IS mm., and fig. 2oh x 8 

 gives only 0"35 mm. 



Several published, small, spherical, more or less reticulate bodies, figured as 

 Orbulinx, which have a diameter of about O'So to 0-72 mm., and relatively large 

 perforations, eight to eleven in number across the shell, might at first sight be 

 referred to as analogues of this little organism, especially if the roughnesses on 

 some of them were supposed to have been worn off. Compare — 



(1) GJobuIijia jwrosa, Tevquem, 1858; OrhuUna porosa, Brady, 1884; 0. vovoaa, 

 Haeusler, 1890; Terrigi, 1890; Egger, 1893. (2) OrhuUna liassica, 

 Terquem, 1862. (3) OrhuUna punctata, Terquem, 1862; Terquem and 

 Berthelin, 1874. (4) OrhuUna neojurensis, Karrer, 1867; Terrigi, 1880; 

 Uhlig, 1883. (5) OrhuUna rnillepora, Terquem. (6) 0. macropora, 

 Terquem, 1876, 1883. (7) 0. Argoviensis, Haeusler, 1881. (8) OrbnUna 

 nitida, Terquem, 1886. 

 Two of these in particular closely resemble our fig. 23 a, and are far more 

 likely to be Eadiolarian than Foraminiferal according to the figures and descrip- 

 tions of them given by M. Terquem, thus : 



OrhuUna macropora, Terquem (from the Bajocian of the Moselle), ' Bulletin 

 Soc. Geol. France,' ser. 3, vol. iv, 1876, p. 481, pi. xv, fig. 1 : " Coquille blau- 

 chatre, translucide, munie des pores tres-grands et espaces; fort rare. Diametre, 

 0-29 mm." 



OrbnUna nitida, Terquem (recent from Christiausand), 'Bulletin Soc. Zoolog. 

 France,' vol. xi, 1886, p. 330, pi. xi, tig. 1 : " Coquille subspherique, lisse, brillante 

 et transparente ; fort rare. Diametre, 0*31 mm." 



The figure (PL III, 23 «) given in 1866 shows, however, that the little sphere 

 is not hollow. Whether a Foi'aminiferal OrhuUna or a Radiolarian Cctiosphsera, 

 perhaps it had been filled with matrix, some of which, entering small holes in the 

 shell, still remains as short rods. If these little rod-like bodies had been more 

 equally proportioned, we might look to the Radiolarian Actinomma (ThecosjjJisera) 

 for an analogue. In this case the short pillar-like rods may have been the " beams " 

 connecting the inner mass with the outer shell by passing into its substance at 

 the narrow spaces between the round holes of the surface. Their relative 

 positions, however, scarcely permit of this interpretation. 



Our fossil is very much larger than the majority of Radiolaria. The perfora- 

 tions of the shell, however, are about the same in number as in some forms of 

 Ethmosplisera and Thecosphsera, and are not relatively larger. 



Of course we have here evidence only of analogy, and not identity. Sup- 

 posing the little fossil to have been coated or thickened with mineral matter, and 



48 



