POEOCIPELLIA.— OPEHYSTOMA. 125 



Genus POROCYPELLIA, Pomel (emend. Zitt. 1877). 



POEOCYPELLIA PYRIPOEMIS, Golclf. sp. 



1826-33. Scyphia pyriformis, Goldf. Petref. 1 Th. p. 10, t. 3. f . 9. 



1877. Porocypellia pyriformis, Zitt. Studien, I Ab. p. 53 ; Neues Jahrbuch, p. 364, t. 5. 

 f. \a,b. 



Distribution. Upper Jura: Streitberg (coll. Zitt.). 



Genus CASEARIA, Quenst. 1858. 



Caseaeia articulata, Goldf. sp. 



1826-33. Scyphia articulata, Goldf. Petref. 1 Th. p. 9, t. 3. f. 8. 

 1858. Casearia articulata, Quenst. Der Jura, p. 681, t. 82. f. 9. 



1877. Casearia articulata, Zitt. Studien, I Ab. p. 54; Neues Jahi'bucli, p. 365, t. 5. f. 2 a, b. 



1878. Spongites articulatus, Quenst. Petref. Bd. 5, p. 107, t. 120. f. 8-10, 12-21. 



Distribution. Upper Jura: Streitberg; Heuberg; Heiligenstadt; Giengen; Randen. 



Genus POROSPONGIA, D'Orbigmj, 1852. 



POKOSPONGIA maeginata, Goldf. sp. 



1826-33. Manon marginatum, Goldf. pars, Petref. 1 Th. t. 34. f. 9^, h. 



1877. Porospongia marginata, Zitt. Studien, I Ab. p. 55 ; Neues Jahrbuch, p. 366. 



Distribution. Upper Jura : Heuberg, Wiirtemberg. 



POEOSPONGIA IMPEESSA, MilUSt. sp. 



1826-33. Manon impressum, Miinst. in Goldf. Petref. 1 Th. t. 34. f. 10. 

 1877. Porospongia impressa, Zitt. Studien, I Ab. p. 55 ; Neues Jahrbuch, p. 366 ; Handbuch 

 der Pal. vol. i. (1878), p. 180, f. 95 a, b, c. 



Distribution. Upper Jura: Streitberg; Muggendorf, Franconia [coll. Zitt.). 



Genus OPHRYSTOMA, Zitt. 1877. 



Ophrystoma miceommatum, Boem. sp. 



1864. Porospongia micrommata, Roem. Pal. Bd. 13, p. 9, t. 4. f. 14. 



1877. Ophrystoma micrommatum, Zitt. Studien, I Ab. p. 55; Neues Jahrbuch, p. 366. 



Sponge growing in flattened expansions of various dimensions. An imperfect 

 specimen is 80 mm. in width. The upper surface is smooth, and is provided with 

 numerous, irregularly disposed, circular or ovate apertures, from 2*5 mm. to 4 mm. in 

 width and from 2-5 to 7'5 mm. apart. When perfect these apertures have distinctly 



