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NEW YORK STATE MUSEUM 



m u r c h i s o n i Billings as to entitle them to generic distinction. 

 The following genus is therefore proposed. 



SIGMACYSTIS nov. 

 Cystidea with two short, main food grooves. The anterior curves 

 strongly to the right and the posterior strongly to the left forming 



i 6 " 



Fig. 35 Si'g'm'acy sti s emmonsi Hudson. From a photomicrograph of specimen C now 

 in the State collection at Albany. The^probable appearance of seven of the ten arms is indi- 

 cated. Several articular facets may be clearly seen. 



together a letter S with the mouth in the center. These food grooves 

 follow a line of sutures, but do not cross sutures unless at the 

 extreme ends. The concave side of each is formed by the raised 

 edge of two orals, while the convex side is formed by the inner 



