[DAWsoNl FOSSIL SPONGES AND OTHER ORGANIC REMAINS 103 



spicules, short, and. in some cases, expaiuied at llioir extremities. Youn^ 

 individuals seem to have been glolnilar and pi-oluihly se„.sile, while large 

 individuals had a flat base; but the general f'onu is greatly obscured by 

 crushing, especially in the larger specimens. 



Fig. m.—Protospungia polynemai Primary, .secondary 

 and tertiary spicafes, x 5. 



4. — rROTOSPONGIA DELICATULA, DaWSOn. 



(Figs. 11 and 12.) 



Globular or oblong in form, 1 to 4 cm. in diameter. Body spicules 

 cruciform, regular, forming a very dense mesh, about 1 mm. or less in the 

 o[)ening. Osculum probably wide. Defensive spicuies very short and 

 close. Several short anchoring-rods. Some indications of a double row 

 of spicules in the body-wall. The density of the spicular body-wall 

 causes it often to be encrusted and obscured by pyrites. 



Fio. 11.— Protosponyia delicatula. {a) Re- 

 stored. (6) Portion of base enlarged. 



Fig. 12.— Primary, secondary and 

 tertiary spicules, x 5. 



Rauff, in his monogra])h on fossil sponges, identifies tliis with Wal- 

 cott's Ct/athophycus {Teijanium) subsphcericus of the Utica shale, but com- 

 parison with specimens kindly furnished by Dr. Walcott shows that there 



