Amongst the large series of specimens of Meyeria recently obtained by the Sedgwick Museum, Cambridge, from the Lower Greensand of Atherfield, Isle of Wight, two new and strange forms, obviously referable to another genus, were detected by me in looking over the material. Their interest consists not only in belonging to new species but in representing the genus Thenops, of which the best known and only British species, so far described, is Th. scyllariformis, Bell, from the London Clay. There is one imperfect specimen in the British Museum from the Speeton Clay attributed (with a query) to Thenops, but no other British representative from the Cretaceous appears to have been found.