THE FORAMINIFERA 



apart of the chambers. A remarkable feature of some Lagenidae is 

 the " entosolenian " condition in which the tubular neck is, as it 

 were, inverted into the interior of the test (Fig. 46, b). A similar 



FIG. 46. 



a, Lagena sulcata, W. and .1. , x 60. b, 

 L. globosa, Montagu, showing the ento- 

 solenian neck. (After Brady.) x 80. 



FIG. 4 



Cristettaria crepidida, F. and M., after 

 Brady (3, PI. 68, Fig. 1), showing the pro- 

 duction of a brood of megalospheric young, 

 of varying size, by a megalospheric parent. 

 X 38. 



inverted neck is found in Cymbalopora, and occasionally in Poly- 

 morphina (3, pp. 558 and 638). 



The observations of Burrows and Holland (5) on Cristel- 

 laria gibba, and C. platypleura appear to show (though no 

 measurements are given) that the authors have found dimorphic 

 forms of Cristellaria. In C. cenomana, Schacko ^(40) describes a 

 form which, he suggests, is micro- 

 spheric, having a central chamber 

 measuring 40 ^ while M = 75 /z. 

 In the specimen of C. crepidula 

 shown in Fig. 47, however, the 

 size of the young chambers (which 

 we may suppose to be megalo- 

 spheres) varies much, and the 

 smallest appear to measure about 

 40 p in diameter; and as this 

 measurement is rather large for 

 the size of a microsphere, the mi- 

 crospheric character of Schacko's 

 specimen is, at least, open to 

 doubt. 



The genus PolymorpMna is FIG. 4s. 



remarkable for the fistulose PolymorpMna compressa, d'Orb. ; c, the 

 , . i_ i simple form, x 32 ; d, the fistulose form, 



branching processes whicn are x ss. (After Brady.) 



developed in the later stages of 



the growth of the test. What relations these may have to the 



life-history has not been determined (Fig. 48, c and d). 



