148 SILICEOUS SPONGES. 



are present on the ridges. No spicular structure has been preserved ; and the 

 specimen is too imperfect for comparison with other species. 



Distribution. Spongarian zone of the Chloritic Chalk {Tate) = Upper Chalk : White- 

 head, near Belfast [Jermyn- Street Museum). 



CCELOPTTCHIUM SeEBACHI, Zitt. 



1876. Cceloptychium Seebachi, Zitt. Abhand. k. bay. Ak. II CI. Bd. 12, p. 68, t. 2. f. 5-7, 

 t. 3. f. 8, 9, and t. 5. f. A. 



1878. Cmloptychium Seebachi, Quenst. Petref. Bd. 5, p. 521, t. 140. f. 3, 4. 



1879. Cceloptychium Seebachi, Nicholson, Manual of Pal. vol. i. p. 143, f. 38. 



Distribution. Upper Chalk; Lemforde, Hanover. 



C(ELOPTTCHiuM SDLCiFERUM, Boemer. 



1841. Cceloptychium sulciferum, F. A. Roemer, Nordd. Kreide, p. 10, t. 4. f. 4. 

 1876. Cceloptychium sulciferum, Zitt. Abhand. k. bay. Ak. II CI. Bd. 12, p. 72. 

 1878. Cceloptychium percussum, Quenst. Petref. Bd. 5, p. 512, t. 139. f. 14. 



Distribution. Upper Chalk : Coesfeld, Westphalia. 



Cceloptychium lobatum, Goldfuss. 



1826-33. Cceloptychium lobatum, Goldf. Petref. 1 Th. p. 220, t. 65. f. II. 

 1864. Cceloptychium lobatum., F. A. Roemer, Pal. Bd. 13, p. 4, t. 2. f. 12. 

 1876. Cceloptychium lobatum, Zitt. Abhand. k. bay. Ak. II CI. Bd. 12, p. 73. 

 1878. Caloptychium sexlobatum, Quenst. Petref. Bd. 5, p. 509, t. 139. f 13. 



Distribution. Upper Chalk ; Coesfeld, Westphalia. 



Suborder LYSSAKINA, Zittel. 



FamUy MONAKID^, Marshall. 



Genus ASTRiEOSPONGIA, F. Bcemer, 1854. 



AsTR^ospONGiA MENISCUS, F. Rosmer. 

 1848. Blumenbachium meniscus, F. Roemer, Leonhard und Bronn's Jahrbuch, p. 680, t. 9. 



f. 1 a-c. 

 1852. AstrcEOspongium meniscus, Bronn's Leth. Geogn. 2 Th. p. 156, t. 5. f. 1 a-c. 

 1860. AstrcBOspongia meniscus, F. Roemer, Die silur. Fauna des westl. Tenn. p. 14, t. 1. f, 6. 

 1878. AstrcBOspongium meniscus, Zittel, Handb. der Pal. Bd. 1, p. 185. 



1878. AstriEospongia meniscus, Quenst. Petref. Bd. 5, p. 557, t. 141. f. 8. 



1879. Astreeospongia meniscus, Nicholson, Manual of Pal. vol. i. p. 135. f. 33 a, b. 



1880. Astreeospongia meniscus, F. Roemer, Lethea Pal. I Th. p. 314, t. 9. f. 2 a-c. 



Sponges growing in the form of concavo-convex disks ; sessile. Specimens vary 



