PROTOZOA. 35 



ance is represented in the Collection both by fossils and 

 by series of drawings. The simplest or most elemen- 

 tary structure in this latter group is to be found in the 

 shell of Lagena (PI. 27, figs. 1,2). Fig. i. Lagena globosa 

 Montagu, shows the globular shell so common as the 

 ground form of the Foraminifera, and fig. 2, Lagena laevis 

 Montagu, represents a flask-shaped modification of the 

 primitive form. The shell of Lagena is a single chamber 

 with a terminal opening. The walls are calcareous and 

 finely perforated for the exit of the pseudopodia. This 

 genus like others exhibits great variation. 



Nodosaria (PI. 27, figs. 3-5, No. 28, N. soluta Reuss.) 

 consists of chambers united in a straight or curved line, 

 with the opening in the center of the terminal chamber. 

 PI. 27, fig. 3, is Nodosaria simplex Silvestri, consisting of 

 two chambers in a straight line, and fig. 4 is another spe- 

 cies of the same genus (Nodosaria subtertenuata Schwager) 

 composed of several chambers. Fig. 5, Nodosaria (= 

 Dentalina) farcimen Soldani, has more chambers and the 

 shell shows a tendency to curve. 



The group represented by Globigerina is one of great 

 interest since the ooze of portions of the deep sea is 

 largely made up of the shells of these Foraminifera. 

 Although existing in such vast numbers to-day, both 

 Globigerina and Orbulina (see p. 36) have been dis- 

 covered recently in the ancient Cambrian formation of 

 New Brunswick. 1 Here they occur well preserved in 

 shales and in phosphate nodules. Sufficient investiga- 

 tions, however, have not been made to prove beyond 

 doubt that this ancient Orbulina is the primitive ancestral 

 form of Globigerina. 



Cayeux's paper 2 is interesting in this connection. He 



1 Matthews, Trans. N. Y. Acad. Sci., XII, 1893; also XIV, 

 March, 1895. 



2 Sur la presence de restes de Foraminiferes dans les terrains pre*- 

 Cambriens de Bretagne. 1894. See also review of M. Cayeux's 

 paper by G. F. Matthews, Amer. Geol., XV, 1895, p. 146. 



