Fig. 2. 
Fig. 6. 
Fig. 21. 
Fig. 22. 
Fig. 28. 
^ 
Figs. 24, 
MERRILL: FOSSIL SPONGE SPICULES. 25 
EXPLANATION OF THE PLATE. 
. Monactinellid. Axinella? sp. Replaced by chalcedonic silica. > 88 
diameters. 
Monaetinellid. Axinella? sp. Replaced by chaleedonie silica. х 20 
diameters. 
4, 10, and 36. Monactinellid. Reniera? sp. Bodies replaced by amor- 
phous silica, canal by chalcedonic silica. X 80 diameters. 
. Monactinellid, acuate spicule. Replaced by chalcedonic silica. X 80 
diameters. 
Monactinellid. Spicules covered with minute projections, canal enlarged. 
x 80 diameters. 
. Monactinellid, dark outer covering, probably iron ore. X 80 diameters. 
. Monactinellid. Replaced by amorphous silica. X 80 diameters. 
. Monactinellid. Esperia? sp. In amorphous silica. X 80 diameters. 
. Tetractinellid. Geodia? Austin’, n. sp. In colloidal silica. X 275 diam- 
eters. 
. Tetractinellid. Geodia? eretacea,n. sp. In colloidal silica? X 275 diam- 
eters. 
. Tetractinellid. Geodia? spini-curvata, n. sp. In colloidal: silica? X 275 
diameters. 
4. Tetractinellid. Geodia? irregularis. In colloidal silica? x 275 diameters. 
. Tetraetinellid. Geodia? tripunctata, n. sp. In colloidal silica. X 275 di- 
ameters. 
Tetractinellid. Hymeraphia? sp. X 275 diameters. 
Tetractinellid, Chondrilla? sp. In colloidal silica? X 275 diameters. 
. Tetractinellid. Geodia? Terana, n. sp. In colloidal silica. X 275 diam- 
eters. 
Tetractinellid. NHymeraphia? sp. In colloidal silica? X 275 diameters. 
. Tetractinellid, Geodia? spini-pansata, n. sp. In colloidal silica? X 275 
diameters. 
Tetractinellid. Geodia? Milli, n. sp. In colloidal silica? X 275diameters. 
Tetractinellid. Geodia tripunctata? n. sp. Fragments resulting from solu- 
tion. X 275 diameters. 
Lithistid? Flesh spieule. X 275 diameters. 
25. Tetractinellids. IIymeraphia? sp. Globostellates in colloidal silica ? 
X 275 diameters. 
