VOL. XVIII. (i) INFERIOR-OOLITE ECHINOIDS 79 



HYBOCLYPEUS cf. OVALIS Wright. PI. VIII, figs. 

 la and b. 



In the Garantiana-Beds of Hadspen a form of Hyboclypeus, 

 nearest to H. ovalis Wright, is not uncommon and is associ- 

 ated with H. subgibberulus sp. nov. (see page 78). 



Most of the specimens are indifferently preserved, so 

 that the exact outUne of the test is somewhat difficult to 

 determine. Compared with the figure given by Wright 

 (Monograph, pi. XXII., fig. i) this form seems to be similar 

 except in one respect, namely, in the relative length of the 

 test. In the forms from Hadspen the outhne appears to be 

 subcircular, the breadth being very sHghtly greater than the 

 length ; while according to Wright's figure, the length is 

 slightly greater than the breadth. 



Wright records his species " only from the marly fossiliferous 

 vein which traverses the upper ragstones of the Inferior-Oolite, 

 in the zone of Ammonites Parkinsoni, Sow., near Hampen, 

 Gloucestershire, where it is associated with Holectypus depressits, 

 Leske, H. hemisphesricus, Desor, Pedina rotata, Wright, Clypeus 

 Hugi, Agass., Clypeus Plottii, Klein, Trigonia costata, Sow., Pecten 

 symmetriciis, Morris, Ammonites Parkinsoni, Sow." 



This association suggests that the date of the deposit is 

 truellei. 



Wright also adds that he has found "one specimen in the Trigonia- 

 Bed at Cold Comfort [near Cheltenham], where it was associated 

 with the large Pevna isognomoides, Stahl." 



The horizon from which this specimen came is doubtful, 

 as there is now no Tngonia-Giii exposed at Cold Comfort, 

 although the Upper Trigonia-Gx\i may once have been seen 

 resting on the Witchellia-Gxii, in which the Perna-Bed, from 

 which many large Pernas have been obtained, occurred. In 

 our main paper (p. 174), the specimen was queried as having 

 come from the Lower Trigonia-Grit {discitce), but in the 

 light of the new record of a closely allied form (perhaps only 

 a local variant) from the Garantiana-Beds of Somerset, it 

 seems more probable that it came from the Upper Trigo- 

 nia-Grit. 



In the main paper a small specimen from the Buckmani- 

 Grit {post-discitce) of Tuffley's Quarry, Crickley, near Chelten- 

 ham, was referred to H. ovalis Wright, being regarded as 

 probably the young of that species. The specimen, however 



