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X. — Remarks on the Foraminifera, with especial reference to their 

 Variahilitij of Form, illustrated by the Cristellarians. — Part II. 



By Prof. T. Eupert Jones, F.E.S., F.G.S., 

 and C. Davies Sherborn, F.G-.S. 



{Read 8th June, 1887.) 



Part I. of this paper, in the ' Monthly Microscopical Journal ' for 

 February 1876, contained a synoptical Table of the published varieties of 

 Cristellaria, from the time of Linne to 1840 ; and an attempt was made 

 to reduce these numerous figured forms to their proper zoological positions, 

 by referring them to the few best-pronounced types of Cristellaria. In 

 the two plates illustrating the above-mentioned paper, there were figured 

 a series of Foraminifera, all belonging to the Nodosaringe; and they 

 exemplified the gradual passage from the straight, many-chambered shell 

 of this kind of Foraminifera to the most perfect spiral form. At the same 

 time it was shown that the cylindrical and compressed shells of varying 

 thickness were merely varieties of the same form. It has been thought 

 advisable to continue the Table as a guide to future workers in this group 

 of Microzoa; and in this paper the Cristellarians are now further 

 zoologically tabulated to the end of 1860. 



It having been found impossible, for want of space, to include those 

 other groups of Nodosarinae which are closely connected with Cristellaria, 

 we have omitted hundreds of references to the many varieties of Margi- 

 nulinse, Vaginulinse, and other sub-groups, which cannot, if regarded 

 biologically, be separated from the Cristellari&e. The most striking 

 series of these omitted forms will be found in a paper by Neugeboren, 

 published in the Verb. Mitth. Siebenburg. Ver. Nat., ii. 1851, where 

 a series of forty-five partially-coiled Nodosarinae are figured, most of 

 which have been elevated by him to the rank of " species." Others are 

 to be found in a paper by M. Cornuel in the Mem. Soc. Geol. France, 

 ser. 2, iii. 1848 ; in Keuss' " Westphahschen Kreide," SB. K. Akad. 

 Wiss. Wien, xl. 1860, &c. 



In drawing up the Table, five forms have been selected as the chief 

 types around which to group the Cristellaria; these are, C. calcar 

 (Linne), representing the keeled and rowelled forms, and of which all 

 spiral Cristellaria are specifically varieties; and, as convenient sub- 

 varieties of this, C. cultrata (De Montf.), representing the keeled forms ; 

 C. rotulata Lam., the keelless forms ; C. italica (Defr.), the triangular- 

 elongate forms ; and C. crepidula (Fichtel and Moll), including all com- 

 pressed-elongate forms. It must, however, be understood that these five 

 varieties are not themselves to be considered as really distinct, but are used 

 merely as available heads of divisions into which the Cristellarise may be 

 sorted. Some few subordinate names are kept, with the alliances indicated. 



In the Table, the middle column gives the names bestowed by 

 different authors upon the varieties which they have described as 

 " species." Those names which we consider to be of suflicient value to 

 be kept for classificatory purposes have been printed in larger type ; 

 while, on the other hand, those which are unmistakably the same as 

 our recognised types are printed in smaller type, to indicate the advis- 

 ability of allowing their pseudo-specific name to drop. There is certainly 



