Spkcxks of the Wavkbly Group. 



153 



and eacli divided across the top by a low furrow. Tlie nodes are vertically 

 elongated, not constricted at the base, and the lobes are low and obtuse. 



The reticulum is composed of very fine spicular bands among which scarcely 

 any difference in size is apparent. There is no evidence of a pnsmatic division 

 of tlie surface. So few specific characters are retained by this single frag. 

 nient that it is referred with considerable hesitation to the genus Tyixjdiotya ; 

 yet its nodose surface suggests such relationship and its occurrence in the 

 same fauna Avith T. Warrenensis enforces this suggestion. 



Locality. In the Waverly sandstone, at Warren, Pennsylvania. 



CLATIIROSPONGIA, HalL 

 (For description see page 121, part 1.) 



Clatiirospongia abacus. Hall. 



Plate xlix, Fiqs. 6-8. 



1882. Clath'ospongia ahacus, Hall. Notes on the Family Dictyospongidaa ; 



Expl. pi. 18, figs. 2-4. 

 1884 Dictyopliyton {Glatlii'ospongid) ahacus, Hall. Thirty-fifth Ann. Kept. 



N. Y. State Mus. Nat. Hist., p. 474, pi. 18 (19), figs. 2-4. 



Sponge of moderate size, regularly turbinate or obeonical ; actual base 

 not preserved, but judging from the slope of the sides, acute. Expansion 

 rather rapid. Aperture unknown. 



Surface bearing coarse jirimary spicular ridges, which enclose quadrules 

 measuring on the average 10 ram. in width and 9 mm. in length. These ai"e 

 subdivided into four squares by the secondary spicular bands; the finer 

 divisions of the reticulum may also be preserved. The primary bands are 

 extended into free horizontal and vertical expansions measuring about 8 mm. 

 in width and the deep fenestrations thus made are divided into smaller areoles 

 by the crossing of the subordinate reticulating bands in each ; this inference 

 is, at least, to be made from the appearance of finer reticulating lines on the 

 surface of the primary expansions. 



Dimensions. Length of the original specimen, 100 mm.- greatest 

 diameter of the cup (at upper extremity), 50 mm.; median diameter, 38 mm. 

 without, and 54 mm. with the lamellar expansions. 



Locality In the sandstones of the Waverly group, associated with 

 Ectenodictya implexa, and an undetermined Spirifer or Syringothyris ; 

 Warren, Pennsylvania. 



