350 
PALEONTOLOGY OF NEW YORK. 
Finally, it is important to emphasize the intimate similarity between Rensse- 
LAERiA and the pentameroid genus Amphigenia ; genera in which the essential 
distinction between the typical forms of each lies in the simple loop of the 
former and the long, expanded but still discrete crural processes of the latter. 
Attention has been directed to these similarities and differences, and it has also 
been pointed out that the spondylium in Amphigenia elongata is at times almost 
reproduced in specimens of Rensselaeria ovoides where the dental lamellae are 
highly developed. 
