26 
Case, No. 15. The shells are usually composed of a number 01 
chambers, the outer of which envelope the inner, with perforations 
{foramina) in the partitions. Orbitoides in the Eocene, Alcove 
Case, No. 14, Dana' s > Manual series, and Fttsulitia, in the Coal 
Measures, Case o, Sect. 6, are large examples. The following 
cut illustrates several of the known forms enlarged. 
Fig. 15. 
6 ode fa 
hi jfc I 
Fig. 15: a, Globigerina rubra; i, Textularia globulosa ; r, Rota- 
lia globulosa ; Grammostomum phyllodes ; Frondicularia an- 
nularis ; _/", Triloculina Josephina ; £, Nodosaria vulgaris ; //, l.ituola 
nautiloides ; /, Flabellina rugosa ; 1>\ Chrysalidina gradata J /, 
Cuneolina pavonia ; m, Nummulites nummularia ; «. Fusulina cyl- 
indrica. All enlarged, except Fig. m, and upper one of «. 
Fig. 16. 
Orbitulina Texana, Nat. Size. 
SPONGES. 
Sponges are found as fossils in many of the geological forma- 
tions, but most of them are very obscure in their characters and 
difficult to recognize. As examples of this form of animal life 
Eo zoon Canadensis and the genus Stromaiopora may be mentioned ; 
these being probably sponges, although not always classed as such. 
See Alcove Case, No. 1 {Dana's Manual series), also Cases 
b, e, h and k. Other forms, as As/ylospongia and Astra:ospon^ia, 
are represented in Cases E and f. There are also some very 
remarkable forms represented under the name Dictyop/iyton, first 
announced as sponges from this Museum ; they resemble and are 
closely allied to Euplectella, the Venus basket, or glass sponge of 
