INVERTEBRATES. 499 



UPPER SILURIAN SPECIES. 



SPONGI^E. 



ASTYLOSPONGIA PRAEMOESA, Goldf.? (sp.) 



PI. 25, Kg. 2 and 2 a. 



AstylosponJjia praemorsa, Goldf., 1826. Petref. Germ., vol. 1, tab. 6, fig. 9 ,■ Heisinger (1837), Leth. Suec. 



94, tab. 26, fig. 7 ; Ecbwald Silur. Scbicht, in Estbland 209 ; Maximilian (1843), Herzog Ton Lencbt. 



Beacbr. einiger neuen Thierreste der TJrvrelt aus den Siluriscb. Kalkacb. von Zarakoje-Selo., 24 ; 



F. Eoemer (1852-1854) ; Leonb. a. Bronn'sJabrb., 684 ; and in Letbae geog. ed., 3d Tb. 154, tab. 27, 



fig. 21. 

 Siphonia ezcavata, Goldf., 1826. Petref. Germ, 1, tab. 6, fig. 8; Bronn (1851-1832), Letb. geog. ed., 3d 



Th., V. 75. 

 Siphonia stipitata, Heisinger. Letb. Suec. 94, tab. XX VT_ fig. 8. 

 Jena excamta, d'Orbignv,'1850. Prod, de Pal. strat. 11, 286. 

 Aslylosptmgiapraemoraa, F. Eoemer, 1860. Sil. Fauna dea Westl. Tennessee, p. 8. 



Depressed subglobose, the breadth being to the hight as 90 to about 

 65 ; concavity of summit shallow ; furrows of sides about 24, somewhat 

 flexuous, and more or less interrupted. (Under side unknown.) Hight 

 1.80 inch, breadth 1.30 inch. 



The only specimen of this fossil we have seen is entirely silicified, and 

 compact in structure (in its present condition), while its surface is con- 

 siderably worn. Consequently we are by do means clearly satisfied that 

 it belongs to the same species as that figured by Goldfttss, Roemee and 

 others, but merely refer it provisionally to that species, until better 

 specimens can be obtained for comparison. On comparing it with speci- 

 mens of the Tennessee form figured by Roemee, it is seen to present a 

 smoother, less porous appearance, but this we believe is due to its worn 

 and more densely silicified condition. It also appears to want the canal 

 openings in the depression of the summit generally seen in the Tennes- 

 see specimens, but this may be due to the accidental filling of these 

 openings with silicious matter. 



Position and locality: Pound loose in Carroll county, Illinois, but 

 believed to be from the Niagara division of the Upper Silurian. 



