Xll 
INTRODUCTION. 
Unplaced groups : — 
Group IX. Testamoebiformia, Carter. Lobose forms. 
a. Test calcareous. — Holocladia and Cysteodictyina , Carter. 
b. Test chitinous. — Ceratestina , Carter. 
Group X. Syringosphseridse, Duncan. Test calcareous, with 
radiating groups of tubules. 
Syringosphceria and Stoliczkaria, Duncan. 
Group XI. Receptaculitidae, Giimbel. Test calcareous, consisting of 
an inner and an outer floor of plates, connected by the tubes of an 
anastomosing canal-system. 
Receptaculite-s, Defrance ; Ischadites, Kdnig ; Tetrayonis , Eichwald ; Spheero- 
nites, Hisinger; Sphcerospongia, Salter. 
In the foregoing Table the names given in parentheses indicate, for the 
most part, not synonyms, but subgeneric relationships, so far as such 
grouping can be admitted where even many of the “ genera ” are artificial 
and not of more value zoologically than “ species ” in higher orders of 
animals. In this infinitely variable Order, so little is known of any real 
differentiation of the sarcode, or of its physiology, that there remain but 
few characters and features of essential value to guide in its classification. 
Besides the investing and the pseudopodial sarcode, of which so little can 
be learnt, there are only the tissue, form, and structural peculiarities of 
the shell for discrimination; and these present very many gradational 
phases, not only among individuals of any one related group, but between 
the great groups themselves. Thus much uncertainty accompanies the 
special naming of any series of fossil Foraminifera, or any series of recent 
forms from a new or little-known dredging-ground ; for, on zoological 
principles, they might fall into generic and specific groups already known 
and named ; whilst, for the sake of convenience in definitely noting 
the somewhat divergent (though closely related) new varieties, the collector 
might wish to apply new distinctive names. 
In choosing among the numerous names already given to notable 
varieties, it is not always possible to preserve uniformity ; for two nearly 
allied, but slightly different, forms may sometimes be noted under one 
name and sometimes under two or more names given by previous writers, 
as opportunity or convenience may guide. 
