Speciks of thk KKOKtrK Guoirp. 17H 



of bascal obcone, 30 mm. ; diameter at base of the cylindrical portion, 70 mm., 

 at the middle, 85 mm. ; at the aperture, 75 mm. 



Localities. In the calcareous shales at Crawfordsville and Indian Creek, 

 Indiana. (Largely from the collection of A, S, Tiffany.) 



ACLCEODICTTA (?) ECCENTKICA, Hall (sp.). 

 Plate uv, Fiqs. 1, 2. 



1882. Phragmodictya eccentrica, Hall. Notes on the Family Dictyo- 



spongidse; Expl, pi. 19, fig. 1. 

 1884. Ectenodictya eccentrica, Hall. Thirty-fifth Ann. Rept. N. Y. State 



Mus. Nat. Hist., p. 476, pi. 20, fig. 1. 



This species was based upon certain discoid bodies, marked by irregu- 

 larly radiating and concentric spicular impressions, which converge about the 

 central area. The aspect of the specimens suggests the basal obcone in 

 Acloeodictya niarsipus, but the reticulation is much finer than in that species 

 and the surface toward the periphery shows undulations with a tendency to 

 plication. Two of the specimens indicate that a portion of the vertical or radiat- 

 ing spicules from opposite quadrants of the disc are continuous over the 

 apical region, Avhile they are crossed by the spicules from the other quadrants, 

 the radial spicular bands thus reticulating with each other. The concentric 

 or horizontal bands also appear to be present on this apical area. No cicatrice 

 is observable in the specimens. 



The specimens which represent this species difEer considerably in size, 

 one having a semidiameter of 50 mm., the other of 80 mm. The entire 

 diameter of another is 55 mm. 



Locality. In the calcareous shales at Crawfordsville, Indiana. 



GRIPHODICTYA, gen. nov. 



Elongate subcylindrical sponges with subequally expanded base and 

 aperture. No diaphragm or basal disc present (?). 



Surface smooth. Reticulum very fine. Skeleton bearing a great number 

 of hexactins with modified arms (oxyhexasters) and umbrella-shaped clavules 

 of various forms. 



Type, Griplwdictya epiphanes, sp. nov. 



The external characters of this sponge are not fully known, but its 

 spicular composition is so totally unlike that of other forms that upon this 



