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Fig. 
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
. Tetractinellid. Hymeraphia? Globo-stellate in colloidal silica? a x 275, 
b x 550 diameters. 
. Tetractinellid. Geodia ? sp. Dermal spicule. X 275 diameters. 
. Tetractinellid. Geodia? sp. Siliceous globate, spicule ornate. X 275 
diameters. 
. Tetractinellid.  Globo-stellate of dermal layer. In colloidal silica? 
x 275 diameters. 
. Geodia? A siliceous globule, body amorphous silica covered with gran- 
ules of iron peroxide. X 275 diameters. 
. Geodia? Pyramidal ог zone spicule replaced by amorphous silica. X 80 
diameters. 
. Hexactinellid. Stauractinella ? sp. Quadriate spicule in amorphous sil- 
ica. X 80 diameters. 
. Hexactinellid.  Stauractinella? sp. Replaced by peroxide of iron and 
amorphous silica. X 80 diameters, 
. Framework of a Hexaetinellid ? Mesh spicule in colloidal silica, X 275 
diameters. 
. Monactinellid. Reniera? sp. Found in outer margin of nodule. Re- 
placed by amorphous silica. X 80 diameters. 
These drawings were all made with the camera lucida by Mr. J. II. Emerton of 
Boston. 
