NOTICE OF PALAEONTOLOGY OF NEW-YORK, VOLUME IV. 159 



A single species of Ccelospira occurs in the Corniferous limestone, 

 which, so far as known, possesses no characters dififering from Caslospira 

 concava of the Lower Helderberg group. 



With this genus are concluded all the genera bearing calcified spires : 

 these appendages, though probably possessed by some of the following 

 genera, were doubtless fleshy or cartilaginous organs, and have not been 

 preserved. 



Under the Family Rhynchonellid^, the species usually referred to 

 the Genus Rhynchonella are shown to differ from recent species referred 

 to that genus ; while at the same time the internal structure and appen- 

 dages of the typical species of the genus {R. loxia ) remain unknown or un il- 

 lustrated. Under these circumstances, the name Stenocisma, proposed by 

 Mr. Conrad in 1841, is revived, and applied to most of the rhynchonelloid 

 forms of the rocks under consideration. Since, however, Rhynchonella 

 has come to be so well known, and many of the species have been described 

 under the generic designation, the name is still retained. The following 

 species are recognized in the Corniferous limestone : 



Rhynchonella [Stenocisma) teihys, 



" " billingsi (in place of R.thalia of Billings ; 



name preoccupied) 

 " « Carolina (n. s.), 



" ? " ? royana (n. s.). 



In the Hamilton group, we have : 



Rhynchonella [Stenocisma) horsfordi^ 

 « " sappho^ 



« ii 



congregata, 

 prolijica (n. s.), 

 dotis (n. s,). 



« «I 



carica (n. s.). 



IJhemung group the following species are des 



Rhynchonella [Stenocisma) eximia, 



" " stephani (n. s.), 

 " " duplicata^ 



(( a 



contracta, 



<( (( 



orbicularis, 



(( a 



sappho var. 



The Rhynchonella venustula = R. cuboides ? and R. submboides of former 

 reports is left under the Genus Rhynchonella, though with doubt regar- 

 ding its true relation. This species is known only in the TuUy limestone, 

 and occupies a very restricted vertical range. 



