A Specimen of Echinocorys showing the plates of the peristome was exhibited at the Conversazione of the Geologists' Association in 1910 by Mr. W. H. Bennett, and has, through the courtesy of that gentleman, been forwarded to me for detailed examination. In view of the perfect preservation of the peristomial structures, and the extreme rarity of their discovery, I have thought it advisable to publish the following short description. A comparison is made between the structure shown in this specimen and that described by Lovén in the young stages of Echinocardium.