552 



Dr. J. R. KiNAHAN on the Genus Oldkamia. 



tlian many forms of living Sertularidee which have been proved to be the 

 same. Intermediate forms between the two exist. 



Fig. 3. OUhamia ratUata. — A cast. Bray 

 Head. The opposite side of this specimen ex- 

 hibits 0. antlqua. 



Fig. 4. OUhamia aiiiigiM. — Creeping form. Gray- 

 stones, county of Wicklow. 



In the manner of their occurrence, Old. radiata and Old. antiqua are simi- 

 lar. Immense beds, or series of beds, often several feet thick, as the section 



Fig. 5. Slab of Oldhamia radiata, exhibiting the ordinary radial character of the animal, a, the elon- 

 gated form, and XY, the depth of the bed. Graystones, cotmty of Wicklow. 



