102 DlCTYOSPONGIDJE, 



other specimens of about the same size have been observed, but the majority oi 

 these are of small size. 



Under this specific name we have included only the slender fonns pos- 

 sessing the expanded aperture. In previous descriptions some much larger 

 subcylindrical b(,)dies have been regarded as pedicels of the same species, but 

 theu- size and general aspect, supplemented by some additional structural 

 details, indicate that these latter forms are quite distinct from typical examples 



of TlIAMNODICTYA. 



Localities. In the beds of the Waverly group. The original example, that 

 shown on Plate 1, fig. 1, is from a shaly limestone filled with Feneatella and 

 Productus, at Richfield, Ohio. Other specimens are from sandy shales and 

 limestones at Cuyahoga Falls, Ohio. 



Thamnobictya Ortoiti, sp. nov. 



Plate uii, Figs. 1, 2. 



This species is represented by an internal cast, in a compact ferruginous 

 sandstone, of the upper or vase-shaped portion of a Thamnodictya. It is a large, 

 some^vhat compressed individual preserving a considerable portion of the 

 aperture. At its lo\ver point, which represents the opening of the pedicel, the 

 surface shows several somewhat unequal clusters of the longitudinal spicules 

 Avhich have been changed to limonite. The impression of the reticulum is fine 

 and rather irregular. There are no predominant vertical and horizontal 

 spicular ridges as in Thaimwdictya Newherryi, but the entire surface is cov- 

 ered by small quadrules about 2 mm. square and these are again divided by 

 minute subordinate bands. The coiirse of the vertical bands is not radial from 

 the base, but they appear to have made a broad simple curve in extending 

 toward the aperture, a feature which may be exaggerated by the compression 

 of the specimen. Along the apertural margin the net- work is much finer than 

 elsewhere. 



The specimen measures from base to aperture, on one side, 80 mm. and on 

 the other, 97 mm.. Its greatest diameter is from one edge of the folded 

 apertural margin to the other ; each of these lateral extremities is somewhat 

 broken but the full measurement was about 150 mm. The lower sides of the 

 cup slope at an angle of about 60 degrees. 



Locality. In the Cuyahoga shale of the Waverly group, Moot's run, 

 Licking county, Ohio. (Named for Dr. Edwakd Okton, of Columbus, Ohio.) 



