THE FAMILY MILIOLIDiE 91 



earliest workers on this group of animals. Lias to 

 Recent. 



Examples. — M. (Adelosii/a) hicornis^ Walker and 

 Jacob sp. (Serjmla bicornis), Kanmacher's edition of 

 Adams's ' Essays on the Microscope,' 1798, p. 633, 

 pi. xiv. fig. 2. 



A neat striate milioline form, fairly common in 

 shallow- water deposits, and very rarely found deeper 

 than 40 or 50 fathoms. It is a well-known British 

 species. Schlumberger has shown that this species 

 belongs to the type AdelosiiKi of D'Orbigny, and that 

 it has a distinct standing of its own in regard to the 

 internal arrangement of the chambers— that is to 

 say, in the dimorphic form B Adelosina has its me- 

 gasphere completely enveloped by the first chamber, 

 which becomes lenticular. It afterwards passes 

 through the biloculine, triloculine, quadriloculine, 

 and quinqueloculine stages. 



M. hicornis occurs in the fossil condition in the 

 Eocene of the Paris Basin and the London Clay, the 

 Miocene of Vienna and Muddy Creek (Victoria), and 

 in the Pliocene of Italy, St. Erth, and Suffolk. 

 Eocene to Becent. (Plate 3, fig. C.) 



M. oblonga, Montagu sp. (Vermiczdicni oblonguin), 

 ' Test. Brit.' 1803, p. 5'2'2, pi. xiv. fig. 9. 



One of the commonest forms of the shallow-water 

 Miliolina'. It is distinguished by its lengthened 

 test, the chambers of which are inflated and smooth. 

 It exhibits sometimes three, sometimes five faces on 

 the exterior of the shell. M. oblonga is found fossil 

 in the Upper Chalk of Taplow, the London Clay, the 



