538 EEV. G. F. WHTDBOENE ON SOME EOSSTLS 



Of the Jurassic species, the Callovian Gh. Sieboldii, Schwager, 

 Beitr. zur mikr. Faun. Jur. ("Wiirtt. Jahresh.1865) , t. 7. fig. 28, has ten 

 spokes and very numerous long teeth ; Gh. atava, Waag. Ben. Geogn.- 

 Pal. Beitr. t. 24. fig. 4, from Gingen, is flatter, with expanded spokes, 

 forming key-shaped openings, and Gh. vetusta, Schw.,MS., Ben. loc. cit, 

 p. 297, from the zone oiAmm. transversarius, seems to differ in its con- 

 vexity, the character of its periphery, and the arrangement of its lower 

 side. Moore, in the British Association Report for 1872, refers to 

 three Liassie and one Oolitic species occurring in England, and having 

 rays varying in number from five to thirteen. The latter, Gh. Gar- 

 penteri, which is the only form he there defines, seems to be much 

 more ornate than either of the two which are now figured. I cannot 

 find that he has published any further description of his species. 



EXPLANATION OF PLATES XV. -XIX. 



In the following list, B.M. indicates fossils in the British Museum at South 

 Kensington, J in the Museum, of Practical Geology at Jermyn Street, and B in 

 the Museum of the Bristol Scientific Institution, those without a letter being 

 my own specimens. Where it was possible the figures and the measurements 

 given in the text have been taken from different specimens of the same shells. 



Plate XV. 



Fig. 1. Ostrea eoncentrica, Miinst., var. munda. Bight valve. J. 



2. ■ Knorrii, Voltz. Left valve ; Bradford Abbas. 



3, 3 a. . Left valve and profile; Fullers' earth, Frome. 



4, 4 a. pyrus. Left valve ; Burnack. B.M. 



5. spkesroidalis. Left valve ; Yeovil Junction. 



6. . Cast of left valve ; Yeovil Junction. 



7, 7 a. Gryphcea abrupta. Left valve, and profile seen from behind ; 



Dundry. B. 



8, 8 a. cygnoides. Bight and left valves ; Broadwindsor. B.M. 



9, 9 a. Sollasii. Left valve, and profile of shell ; Dundry. B. 



10, 10 a. Exogyra Davidsoni. Left valve and hinge of the same, seen 



from the right. Frocester. 



11, 11 a. ■ globulus. Cast of left valve, front view and profile ; Dus- 



ton. B. M. 



12, 12 a. Pecten fenestrates. Bight valve, and magnified surface. Brad- 



ford Abbas. 



13, 13 a. intermittens. Bight valve and a portion of surface, mag- 



nified. Birdlip. 



14, 14 a. spinicostatus, Eth., MSS. Bight valve and magnified 



surface ; Dundry. B.M. 



15, demisms, Ph., var. inutilis. Fragment showing colour, completed 



from another specimen ; Yeovil Junction. 



16, 16 a. P lacuna Eupertina. Cast of left valve, showing hinge-line, 



cartilage-ridges, and muscular impression ; and profile of the same 

 valve; Duston. B.M. Xf. 



17, sagittalis. Bight valve ; Dundry. 



18, Harpax Tawneyi. Interior of left valve ; Dundry. B. 



19. . Enlarged portion of another specimen, in which the 



hinge is more perfect ; Dundry. B. 



20, Parkinsoni, Qu. Bight valve ; Yeovil Junction. 



21, 21 a. Plicatula Sollasii. Bight valve, nat. size and magnified 3 dia- 



meters ; Dundry. 



22, 22 a, 22 b. ■ . Left valve, nat. size and magnified 3 dia- 



meters ; and profile of the same specimen ; Dundry. 



