Fossil Keticulate Sponges. 475 



than 80 mm. In the middle of its length it has a width of 40 mm., 

 and the greatest breadth above is 105 mm. 



Formation and localities. In the Waverly sandstone ; Harrisville 

 and Akron, Ohio. 



DlCTYOPHYTOK CYLINDEICUM. 



Dictyophytoii cyclindricum, Whitfield. Bulletin No. 1, Am. Mus. Nat. Hist., 

 p. 19, pi. 4, fig. 3. 1881. 



The specimen described in the Bulletin of the American Museum 

 of Natural History is apparently a portion of a flattened cylindrical 

 tube, showing very fine surface reticulations, in which the stronger 

 striae are not preeminently conspicuous, but sufficiently so to divide 

 the surface into quadrules of finer reticulations. The coarse trans- 

 verse and longitudinal rod-like spicules are shown in the specimen, 

 but they do not afford any specific characters under the microscope. 

 The fragment is incomplete at both extremities, having a length of 65 

 mm. and a width in its compressed condition of 57 mm. In its sur- 

 face markings the specimen bears no very close resemblance to any 

 other known species. 



Formation arid locality. In the shales of the Keokuk group ; 

 Orawfordsville, Indiana. 



ECTEtfODICTYA IMPLEXA. 



Plate 19, Fig. 1. 



Dictyopliyton implexum, Hall. Notes on the Family Dictyospongidae ; pre- 

 • lim. to the 35th Rept. pi. 18, fig. 1. 1882. 



Frond a reticulate expansion, assuming a variety of form from pres- 

 sure or other causes ; the original form has been apparently broadly 

 funnel-shaped or ovoid. Base unknown. 



Surface cancellate by strong concentric and vertical striae; the inter- 

 mediate spaces finely reticulate by filiform striae, which cross each other 

 rectangularly. The body presents prominences, or protuberances, 

 which are not sufficiently elevated to be termed nodes. 



A large imperfect specimen, which is distorted by compression, has 

 a length of 180 mm. and a width of about 93 mm. 



The specimens of this species are all more or less distorted ; they 

 appear as broad funnel-shaped expansions without evidence of a dis- 

 tinct tubular base, and are usually fragmentary. 



Formation and localities. In sandstones of the Waverly group, at 

 Warren and Oil City, Pa. 



ECTENODICTYA EXPASTSA. 



Plate 2Q, Fig. 10. 



Phragmodictya ? expama, Hall. Notes on the Family Dictyospongidae ; pre- 

 lim, for the 35th Rept., pi. 19, fig. 10. 1883. 



Frond explanate, discoid or flabelliform. Base unknown. 



