DlCTYOSPONGID^E. 



347 



and quite strongly so at the margins, the elevations there being elongated and 

 extended for some distance over the basal surface ; presenting an aspect simi- 

 lar to this part of the cup in Th. Edwin-Hall i and Tit. rudis, of the Chemung 

 group. 



The reticulum is irregular, as in all of these basal disks which have been 

 subjected to compression, but at certain spots a strong reticulation is retained, 

 composed of major quadrules measuring about 6 mm. on a side, subdivided by 

 two or three series of subordinate bands. The primary ridges are elevated 

 and indicate a strong and coarse net-work over the lateral walls of the cup. 



The diameter of this disc is 150 mm., a size which is not attained by 

 specimens of any other species of the genus. 



Local it a . In the sandstone of the Waverly gronp, Warren, Pennsylvania. 



CALATHQSPOHGIA, gen. nov. 



1863. Bictyophyton, Hall. Sixteenth Ann. Rept. N. Y. State Cab. Nat. 

 Hist,, p. 88. 



1882. Phragmodictya f, Hall. Notes on the Family Dictyospongidse ; Expl. 

 pi. 17, fig. 9. 



1884. Bictyophyton ?, Hall. Thirty-fifth Ann. Rept. N. Y. State Mus. Nat. 

 Hist., p. 474. 



Stout, subcylindrical cups, with truncated bases, without basal cone or 

 diaphragm as far as known, but probably attached by the basal margins ; 

 contracted medially and more or less expanded at the aperture. Surface 

 without nodes or other ornament. 



Type, Bictyophyton Redfieldi, Hall. 



Calatiiosponoia Hedfieldi, Hall (sp.). 



Plate xlviii, Figs. 1, 2; Plate xlix, Figs. 1-4. 



1863. Bictyophyton Redfieldi, Hall. Sixteenth Ann. Kept. N. Y. State Cab. 



Nat. Hist., p. 88, pi. v, fig. 1 ; pi. v a, fig. 1. 

 1882. Phragmodictya ? Redfieldi, Hall. Notes on the Family Dictyo- 



spongidae; Expl. pi. 17, fig. 9. 

 1884. Bictyophyton f Redfieldi, Hall. Thirty-fifth Ann. Kept, N. Y. State 



Mus. Nat. Hist., p. 474, pi. (17) 18, fig. 9. 

 1889. Bictyophytwm Redfieldi, Lesley. Dictionary of Fossils, p. 200. 



Sponge large, probably subcircular in cross-section; base broad, expanded 

 at the margin; the basal expansion continues for about one-third the length of 



