12 



NEW YORK STATE MUSEUM 



and upper Dicellograptus shales of Canada, and is also not unfre- 

 quent in the lower Dicellograptus or Normans kill shales of New 

 York. In the conglomerate of Bysedorph hill it was found 

 embedded in black compact limestone, associated with Ptery- 

 go met opus c a 1 1 i c e ph a 1 u s, Am pyx ha status, 

 Callopora multitabulata. (Group 5) 



CRINOIDEA 



Joints of stems only are found to constitute some gray lime- 

 stone pebbles of Rysedorph hill. (Group 7) 



CYSTIDEA 



Plates of PalaeO'Cystites semira diatus Billings 

 were found in the crystalline, black Ohazy limestone, and a few 

 plates of a Glyptocystites in the compact, black Trenton lime- 

 stone, associated with Illaenus americanus and species- 

 of Tretaspis. (Groups 3 and 5) 



BRYOZOA 



stomatopora Bronn 

 Stomatopora inflata Hall sp. 



Alecto inflata Hall. Pal. N. Y. 1847. 1 :77 



PI. 1, fig. 2, 3 



Zoaria of this pretty bryozoan were found to grow frequently 

 on the cranidia and pygidia of Isotelus maximus in the 

 black compact limestone ; they show the characters of the species 

 as first described by Hall and later more fully defined by Ulrich. 

 A finely preserved group attached to a Rafinesquina 

 d e 1 1 o i d e a shows a remarkable variation from' the typical 

 expression of Stomatopora i n f 1 a t a in having the zooecia 

 abruptly contracted, and the proximal end tubular and slender, 

 thus closely approaching a form described by Ulrich as 

 Stomatopo r»a t u r g i d a from the upper beds of the " Hud- 

 son river group" at Wilmington 111.; the difference between the 

 two consisting in the more spheric shape of the inflated part in 

 the Hudson river form and the more pyrif orm to cy'lindric develop- 

 ment of the same part in the Kysedorph hill specimens (fig. 3). 

 The lack of frequent branching is also common to both. 



