THE FAMILY LAGENIDiE 187 



to have flourished best during the Mesozoic and 

 Tertiary periods. 



The Nodosarines are characterised by a plan of 

 successional growth of lageniform chambers joined in 

 a monihform series and variously modified. In the 

 next sub-family, the Polymoephinin.e, the chambers 

 are arranged side by side, or wound spirally round a 

 common axis of growth. 



The fourth sub-family, the Kamulixix.e, includes 

 tw^o genera, which in their early stages show 

 afiinities towards PoI/jhkjijjJuiki, but which afterwards 

 grow erratically and consist essentially of branching, 

 tubular chambers. 



Suh-familij 1. Lagexix.e. 

 Test monothalamous, hyaline, finely perforate. 



Genus Lagena, Walker and Boys. 



A single-chambered shell, with either an ectoso- 

 lenian or an entosolenian orifice ; sometimes disto- 

 mous apertures at both ends. Shell-surface either 

 smooth or variously decorated with stria?, puncta- 

 tions, ridges, or polygonal meshw^ork. Cambrian to 

 Recent. 



Examples. — L. -s-^^/crtz'rt, Walker and Jacob, Adams's 

 ' Essays,' Kanmacher's ed., 1798, p. 634, pi. xiv. 

 fig. 5. 



The present example affords one a good idea of 

 the typical ectosolenian and flask-shaped Lagena. 

 This species and its allies are often met with in the 



