Fossil Eeticulatb Sponges. 477 



A compressed specimen lias a length of 95 mm. and a width at the 

 base of 55 mm.; at the outer margin near the aperture it is 100 mm. 

 measured between the same bands of spicules. 



Formation and locality. In the calcareous shale of the Lower Car- 

 boniferous group ; Crawfordsville, Ind. 



Thamnodictya Newberryi. 



Plate 18, Figs. 10,11. 



Dictyojjhyton Newberry i, Hall. Sixteenth Rept. on the N. Y. State Cab. of 

 Nat. Hist., p. 87, pi. 4, figs. 1-3. 1863. 



Frond abruptly attenuate near the base, cylindrical above, becoming 

 infundibuliform toward the aperture. 



Surface strongly marked with radiating and concentric stride; the 

 stronger ones in both directions nearly equidistant, except near the 

 intercalation of a radiating band, between these striae are quadrules 

 of finer reticulations.- 



In a well-preserved specimen there is a series of more distant and 

 stronger radiating and concentric striae, which are nodose at their 

 junction. The radiating striae divide the surface into twelve subequal 

 areas ; which features prevail both upon the pedicel and the expanded 

 frond. 



A separated pedicel has a length of 150 mm., and in its compressed 

 condition it has a longer diameter near the base of 46 mm., with a 

 shorter diameter of 15 mm. At the upper portion, where it begins 

 to expand, it has a longer diameter of ho mm., and a shorter diameter 

 of 16 mm. A small specimen shows a portion of the pedicel about 

 40 mm. long, with the infundibuliform expansion of about 50 mm. in 

 length. The diameter of this portion in its flattened condition is 

 about 100 mm. 



Formation and localities. In the shaly and laminated sandstone 

 of the Waverly group ; at Cuyahoga Falls, and in more shalv beds at 

 Richfield, Ohio. 



Phragmodictya catilliformis. 



Plate 18, Figs. 12-14; PI. 20, Figs. 2, 3; PI. 21, Figs. 1-6. 



Dictyophyton catilliforme, Whitfield. Bulletin No. 1, Am. Mus. Nat. Hist 

 p. 18, pi. 3, fig. 1. 1881. 



Phragmodictya scyphus, Hall. Notes on the Familv Dictyospongidce ; pre- 

 lim, for the 35th Rept., pi. 17, figs. 12, 13; pi. 19, figs. 2, 3: pi. 10, figs. 1- 

 6. 1882. 



Cup subcylindrical, or more or less gradually or rapidly expanding 

 to near the aperture. Walls of the cup supported by a strong trans- 

 verse septum and surrounded by an irregular plicate expansion of the 

 substance of the tube. Frond composed of finely reticulate tissue. 



Surface ornamented by elongate nodes and ridges. The expansion 

 from the base is sometimes regularly plicate and the margin scol- 

 loped, showing the same reticulate tissue that pervades the entire 

 frond. The septum is concavo-convex and composed of fine reticu- 

 late tissue with stronger radiating striae. 



