THE 



MONTHLY MICROSCOPICAL JOURNAL, 



FEBEUAEY 1, 1876. 



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

 Variahility of Form, illustrated hy the Cristellarians. 



By Professor T. Kupert Jones, F.E.S., F.G.S. 



{Read before the Eotal Microscopical Society, December 1, 1875.) 



Plates CXXVVI., CXXIX. 



Contents. 

 Introduction. 



Systematic grouping of the Foraminifera. 

 Shells of the Imperfiirata. 

 Shells of the Arenacea. 



Shells of the Perforate or Hyaline Foraminifera. 

 The Hyaline Foraminifera. 



Lagenida. 



Lagena. 



Nodosaria, Cristellaria, &c. 



Cristellaridea. 



Gradations of the Cristellaridea. 

 Conclusion. 



Remarks on the Cristellarians figured in Plates CXXVIII. and CXXIX. 

 iu illustration of their Variability. 



Introduction. — This paper is not intended to be exhaustive ; and, 

 with little that is novel, it aims at giving a general view of the 

 structure and affinities of the Foraminifera and of their extreme 

 variability. 



As is well known to Microscopists, foraminiferal shells can be 

 obtained from numerous marine sands, silts, muds, and clays, recent 



DESCRIPTION OF PLATES CXXVIII. AND CXXIX. 



Plate CXXVIII. 



F[G. 1. — Max von Hantken's 'Die Fauna der Clavulina-Szaboi-Schichten,' 1875, 

 p. 23, pi. 2, fig. 5 (part). Nodosaria Beyrichi, Ncwjeh* ( = Nod. radi- 

 cula, Lin.), a, side ; 6, end, with radiate terminal orifice. 



,, 2.— V. Hantken, p. 29, pi. 3, f. 1-i (part). Dentalina soluta, Bcuss. 



„ 3. — V. Hantken, p. 45, pi. 4, f. 12 (part). Marginulina pediformis, 

 Borneinann. 



„ 4. — V. Hantken, p. 4fi, pi. 5, f. 9 (part). Marginulina subbullata, Hantk. 



„ 5. — V. Hantken, p. 58, pi. 7, f. 1 (part). Robulina Buden^is, Hantk. 



„ 6. — V. Hantken, p. 87, pi. 4, f. 11. Marginulina splendens, Hantk. a, side; 

 6, inner edge. 



[Fig. 7. 



* "Nodosaria Neugebortni, Reuss," in the explanation of the Plate. 

 VOL. XV. F 



