THE FAMILY CHEILOSTOMELLID.E 181 



Lastly, in Seahrool'ia, a form which has been 

 discovered within recent years, we have a modified 

 CheilostomeUa, in which the chambers are not so 

 strongly inflated, and the aperture occupies a position 

 at the apex of the shell instead of at the point of 

 junction between the two chambers on one side of the 

 test. 



The members of this family were first recognised 

 in the fossil state, and two of the genera, Cheilosto- 

 Diella and AllcmiorjjJiina, formed the family Crypto- 

 stegia of Keuss. 



Genus Ellipsoidina, Seguenza. 



Test uniaxial, segments oval, each springing from 

 the base of the previous one and entirely enveloping 

 it ; aperture terminal. Miocene to Post-Tertiary. 



Example. — E. elUpsoides, var. ohlonga., Seguenza, 

 'Eco Peloritano,' ser. % vol. v. 1859, fasc. 9 (13), pi. 

 — , fig. 4 rt, h; Brady, 'Quart. Journ. Geol. Soc' 

 vol. xliv. 1888, p. 5, pi. i. fig. 1. 



This form, as well as the type species, was origi- 

 nally described from specimens out of the Miocene 

 strata of Messina. Dr. Brady discovered, since then, 

 other examples from the late Tertiary or post-Tertiary 

 rocks of the Solomon Islands and from the ' Soap- 

 stone ' of Fiji. 



The section of the shell shown in fig. a of pi. 10 

 gives the position and appearance of the peculiar 

 shelly pillar connected with the ends of each succes- 

 sive chamber. This genus has not been found in 

 deposits actually forming at the present day. (Plate 

 10, figs. A, a.) 



