156 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.46. 



covered with low radiating folds, which increase in number toward 

 margin of umbel, where about 35 arc present. Umbel subcircular, 

 with greatest diameter 33 mm. Entire height of sponge 20 mm. 

 No ostia are apparent, 



A vertical cross section near the edge of the umbel gives indication 

 that although the arrangement of the folds upon one side of the 

 specimen is so poorly preserved as to be indeterminate, yet the 

 apparent connection of the folds on the opposite side in pairs seems 

 to indicate that there was originally present the typical sigmoid 

 arrangement characteristic of Cosloptychium, as seen in C. agancoides, 

 C. deciminum, etc. 



This specimen differs from the typical species of Coeloptycliium in 

 the rounded instead of flattened margin of umbel and in the less 

 elevation of the folds, though this latter feature may be due to 

 imperfect preservation. It approaches C. seebacJd and C. princeps 

 in the depressed upper surface of umbel and in the gradual contraction 

 of its lower surface into the stalk.^ 



Occurrence. — Cretaceous, Mount Laurel-Navesink beds at Atlantic 

 Highlands, New Jersey. 



Holotype.— Cat. No. 31176, U.S.N.M. 



1 Abh. k. bayer. Akad. Wiss., math.-physik, classe, vol. 12, pi. 2. 



