ER01I THE IXEEEIOE OOLITE. 537 



t. 61. figs. 2, 3. They give as synonyms Cid. spatula, Thurm. (non 

 Ag.), and G. copeoides, Quenst. (non Ag.), stating that it differs 

 from C. copeoides, Ag. Cat. Ech., by its narrow and often long neck, 

 fine marks, and absence of large spines at the base, and often is 

 several inches in length. In our specimen the presence of large 

 basal spines is very evident, but in other respects it might well 

 agree with the Oxfordian form, so far as its upper surface goes, while 

 it differs more from Rh. copeoides, Ag., in Desors ' Synopsis,' p. 41, 

 and t. 9. figs. 3-7, both in the shape of its shoulders and the fine- 

 ness of its markings. The latter is quoted from the Inferior 

 Oolite as well as the Oxford Clay of the continent. Gidarites remus, 

 Quenst. Jura, t. 48, fig. 25, and t. 79. fig. 61, seems to differ in the 

 presence of a row of coarse lateral teeth or spines, and, as figured 

 in the new edition of his ' Petrefactenkunde,' seems verj T unlike. 



Considering the differences displayed (especially if the median 

 groove be a permanent character) and lowness of the horizon, it 

 seems to me most probable that this will prove to be a distinct species ; 

 but, from the insufficiency of the material at command, I have merely 

 given it for the present as a variety of the form which seems to 

 approach most nearly to it. 



Chieodota coxvexa, n. sp. Plate XIX. figs. 14, 14a. 



Spicule with large central nucleus, from which spring seven spokes, 

 which are flat, massive, and much arched, and increase in width 

 towards the margin. These unite with the upper side of a vertically 

 flattened circumference, which is in the same plane as the nucleus, 

 and is compressed at the part where each spoke meets it, so as to 

 present a rather seven-sided appearance. The peripheral band is of 

 about the same width as the spokes, and curves inwards, so that its 

 free margin, which is smooth, is rather nearer to the nucleus than 

 the attached one. 



This minute fossil comes from the Inferior Oolite of Burton 

 Bradstock, and is very similar to that figured by Terquem & 

 Jourdy in the Memoirs of the Geological Society of France, ser. 2, 

 vol. ix. t. 15. figs. 8, 9. - These organisms, which have occurred in 

 the Oxfordian and Inferior Oolite of Wiirttemberg, the Great and 

 Inferior Oolite of Prance, and the Inferior Oolite and Middle Lias 

 of India, are supposed to be the spicules of Holothuroids ; and the 

 present fossil agrees in general form with recent specimens with 

 which I have compared it. 



Chtrodota ? geacillima, n. sp. Plate XIX. figs. 15, 15 a. 



JSTucleus small, circular, with about fifteen fine convex rays, which 

 join the upper side of a rather broad peripheral band, which is 

 flattened perpendicularly to the plane of the circle and concavely 

 to the nucleus. The free margin is notched with very numerous 

 (26) small triangular teeth. 



Locality. Burton Bradstock. 



This is a much finer, slighter fossil than the last one, from which 

 it entirely differs in appearance. 



2^2 



