Nomenclature of the Foraminifera. 231 



the radiate, the sinuate, and the reticulate, typified respectively 

 by Nummulina planulata, Lam., N. cumplanata, Lam., and N. 

 laevigata, Lam. The "granulate" and the "explanate" groups, 

 also used by MM. D'Archiac and Haime, we do not recognize 

 as essential, — the former being founded on a character common 

 to each of the three above-mentioned groups (and misunderstood 

 by our authors), and the latter also depending on a modification 

 of structure occurring in two at least of the other groups. 



What we have now to consider is — which of the Nummulina* 

 are, for the purposes of zoology, to be accepted as specific forms. 

 As before stated, we regard as types those Foraminifers that 

 present a fair average of the characters proper to the species, 

 and are neither the simplest of the group, nor necessarily the 

 largest and most richly provided with the peculiarities of struc- 

 ture found in the group. 



We must once more remind the reader that we do not object 

 to binomial appellations as distinctive terms for well-marked 

 varieties of Nummulina' or other Rhizopods. In this case, how- 

 ever, the subject of which we are treating is real specific rela- 

 tionship. 



When we tabulate the fifty-five Nummulina described as species 

 by MM. D'Archiac and Haime in their Monograph, we find six 

 that are simply radiate : these are all of small size (6 millimetres 

 and less in diameter) ; two of them are granulate (N. Miscella 

 and N. Lucasana), and four are smooth (N. Ramondi, N. Guet- 

 tardi, N. variolaria, and iV. Heberti : the last two have the radii 

 slightly curved). 



There are two, N. Rouaulti (granulate) and N. curvispira 

 (each less than 12 millimetres in diameter), that are simply ra- 

 diate, but the septal lines are not quite straight. N. mamillata 

 is an Assiline subvariety of N. Rouaulti. 



N striata, a small form, is simply radiate in some varieties, 

 sinuo-radiate and sinuate in others. 



There are four that are radiate with a slight sinuosity of the 

 septal lines (N. contorta, N. obesa, N. Vicaryi, and N. discor- 

 bina : the first and the last are less than 12 millim. in diameter ; 

 the second attains a diameter of 12 millim., and the third of 

 18 millim.). These are all smooth. 



There are five having sinuo-radiate septal lines : viz. 



N. Vasca, not attaining 



N. planulata, attaining 



N. Viquesneli, attaining 



N. Beaumonti, not attaining 



N Biaritzensis, attaining 



The last-mentioned, however, exhibits both the radiate and 

 sinuo-radiate style of growth in different individuals. 



> a diameter of 12 millimetres. 



