10 AXEL GOÉS, ARCTIC AND SCANDINAVIAN FORAMINIFERA. 



quiries may bring tbrth sevei"al instances of this category, and it would consequently be 

 found that a great deal of arenaceous fonns are too nearly allied to the calcareous ones to 

 be grouped so far asunder from one another as usually they have been. NEUMAyR's dispo- 

 sition of the Foraminifera in 5 families, some containing arenaceous genera coordinated 

 with the homogen-calcareous ones, is very acceptable as being more consistent with our 

 notion of the close alliance between the agglutinating and not agglutinating forms of 

 Textularice and MiUolince. Whether the difPerent genera in Neumayr's system in every 

 instance have been ranged under their proper tribus or place of affinity, is a question 

 that may be subject to a variance of opinions, but his device is worthy of the Rhizopo- 

 dologists great attention. For deciding in these matters we are in demand of far more 

 extensive assemblages of forms both recent and extinct than as yet have come to notice. 



As to the "arenaceous" group, in its present usually adopted ai-rangement, there 

 would be some reasonable ground for objections even concerning the disposal of its sub- 

 families and their genera. Some of these sub-families are apparently in want of true na- 

 tural distinctions, for we are not able to consider the nature of the cementing and the 

 smoothness of the surface as of sufficient distinctive value for instituting families and 

 genera (Cnf. Brady, Challeng. Rep. 9, 1884, p. 63 — 67). On such tickle ground the tribus 

 Rhabdammineaä has been splitted up in 9 genera. The Lituolinete have been subject to the 

 same treatment. The limits between the Nodosarina-like Lituolaj and the Nautiloid ones 

 are as faint as between the true Nodosarinte and their allied Cristellarise. 



Under the subfamily Trocliamminem the most heterogenous forms have been ranged 

 on account of their tests being more finely agglutinated and compacter than in Lituolinece ; 

 and far apart from both these subfamilies have been placed the closely allied Cyclam- 

 minece on no other ground than the cellulär or cancellated condition of the shell-wall in 

 the larger forms of the family, while these features are sometimes wanting in the smal- 

 ler ones. 



With these few remarks on the usually adopted plan of systematizing this class I 

 have intended only to convey to the interested student an idea of the several blänks in 

 our information regarding the real affinities between the genera änd forms in question. 



For much valuable assistance in preparing this synopsis I have to acknowledge my 

 great obligation to Professor S. Loven who has put at my disposal for examination the 

 whole collection of Rhizopodes belonging to the Swedish State-Museum. 



Professor G. Lindström, of the Palseozoic Departement of the same Museum, has 

 with unremitting interest kindly communicated to me papers of låter dates on the subject 

 which, withou.t such an able assistance probably would have escaped my notice. To Mr. 

 Charles David Sherbom in London I am greatly indebted for communicating to me his 

 most valuable Bibliography of the Foraminifera which publication is indispensable to the 

 study of this class. 



Sincere thanks are also due to the well-known Rhizopodologists MM. Joseph Wright 

 of Belfast and Fortescue Millett in Cornwall which gentlemen with the greatest libe- 

 rality have furnished me with type-samples from their own and other english writers' 

 descriptive papers. 



