KONGL. SV. VET. AKADEMIENS HANDLJNGAR. BAND. 19. N:0 4. 11 



I . u Nodosarina type = apertura rotundata, testa recta, teres vel subteres, cameris in 

 seriem dispositis: Nod. radicula LIN. + Nod. scalaris BATSCH. 



'2. a Dentalina type = apertura rotunda, testa arcuata, teres, cameris in seriem dispo- 

 sitis: Nod. communis D'()RB. + Nod. obliqua LIN. 



3. a Orthocerina type (Rhabdogonium Rss.) apertura rotundata, testa tri-tetragona: 

 Nod. quadrilatera D'ORB. + 0. 



4. a Vaginulina type = apertura rotundata, testa plus minusve compressa, plerumque ar- 

 cuata, cameris in seriem plerumque dispositis: Nod. legumen LIN. + Nod. linearis 

 MONT. 



5. a Cristellaria type = apertura rotundata vel trigona, testa plus minusve helicoidea: 

 Nod. calcar LIN. + Nod. costata FICHT. & MOLL. 



6. a Glandulina type -- apertura rotundata, testa recta, teres, cameris equitantibus vel 

 amplectentibus : Nod. Isevigata D'ORB. f Nod. glans D'OuB. 



7. a Frondicularia type = apertura plerumque rotundata, testa compressa, cameris equi- 

 tantibus: Nod. complanata DEFK. + Nod. striata D'ORB. 



8. a Lingulina type = apertura rimceformis, testa plerumque recta, compressa, cameris 

 in seriem plerumque dispositis: Nod. (Lingulina) carinata D'ORB. + Nod. (Lingulina) 

 costata D ORB. 



Such would be a sketch of this genus in a systematic and descriptive sense. 

 But we must be prepared to find, that this mode of arrangement answers but imper- 

 fectly to the natural order of things, for between each of these 15 16 species or types 

 we shall meet with a host of varieties and intermediate forms. For their place in the 

 system many of these depend mostly on the tact and discrimination of the syste- 

 matist. 



The list of synonyms is a fair exhibition of the links, which exist between the 

 typical species. 



In the same way we meet with intermediate links between the smooth species and 

 the corresponding striated ones of both series. And we shall therefore get into no less 

 embarassment, if we look out for specific characters in the condition of the surface of the 

 shell. For every species of the sedans-series will sometimes be found to loose its 

 ornamentation by age, the later chambers becoming smooth (= itsemistriatCBn, semi- 

 nudce); or the chambers are only partially marked with ribs and lines ( mntermit- 

 tentes*) or very sligthly striated (= sublaives). It is for this reason more consistent 

 with the usual conception of species, and also more agreeing with a philosophical and 

 less confusing method of arrangement, after all, to consider the striated and ribbed 

 Nodosaringe as too closely allied with their corresponding smooth forms for to rank 

 them as distinct species. In this respect we readily accept the method followed by 

 Professor WILLIAMSON in his classical treatise 0n the recent Foraminifera of Great 

 Britain*. 



Between Nod. radicula LIN. and Nod. monile SOLD, there seems at the first glance 

 to be a wide interval of difference and yet it will be found impossible to claim for the 

 latter the rank of species. Neither can N. radicula be well distinguished from Nod. 



