154- FOSSIL FAUNA. 



PLATE LXVII. — continued. 



valve. " This is generally filled with limestone, which conceals the internal struc- 

 ture ; but, with a slight blow, the shell divides, when the edge of the small valve 

 rests against the inside of the produced cylindrical part of the larger one ; generally 

 about half an inch from the top of the shell : one side of the valve, before hidden, 

 fig. 9 a, is then exposed, as shown in fig. 10." — 3Ir. Parkinson. 



Fig. 9. a, the beak of the upper valve ; c, a cavity in the superior part of the shell. 



Fig. 10. The under part of the shell; b, a depression receiving the beak of the upper valve, a. 



Fig. 10*. The inner surface of another upper valve, having a longitudinal fissure. The species 

 figured is the Productus Martini of Mr. Sowerby. From the mountain limestone of 

 Derbyshire ; in which deposit numerous examples occur. 



Fig. 11. a large species of Spirifer {Spirifer striatus, of Sowerby), from the mountain limestone 

 of Derbyshire. In this species the upper valve is broken away, and one of the lar^e 

 spiral apophyses is seen lying imbedded in the limestone with which the cavity of the 

 shell is filled. 



Fig. 13, is a beautiful example of part of one of the spiral appendages of the same species. 



Fig. 12. "A patch of square scales of a fish from Dorsetshire." — Mr. Parkinson. These 

 evidently belong to a Lepidoid fish {Dapedius), whose remains are common in the 

 Lias ;' perfect specimens are often obtained. The British Museum contains some 

 beautiful examples of this fossil fish. 



Figs. 14, St 15. A curious fossil bivalve, from the Devonian strata of the Eifel. The flat valve 

 is shown in fig. 14; and the deep conical valve in fig. 15 ; a, tooth in the posterior 

 margin; b, a part of the surface magnified, to show its cellular structure. The 

 species is Galceola sandalina, of Lamarck. 



Fig. 16. A species of Spirifer; a, medial convexity of the upper valve; b, the triangular foramen 

 at the beak. 



Fig. 17. Spirifer {S. cuspidatus, of Mr. Martin), from the Mountain limestone of Derbyshire. 



Fig. 18, represents a common appearance in certain chalk flints. Although I have examined 

 hundreds, and some in which the form was more definite than in the specimen 

 figured, I am not able to offer any probable suggestion as to their origin, should they 

 be organic bodies, of which there is much doubt. 



Fig. 19. " Coronulites diadema:'—Mv. Parkinson. Probably a species of Balanus, from a tertiary 

 deposit. 



Fig. 20. Cast of one of the shells of a bivalve {Pentamerus), from the Wenlock limestone of 

 Dudley. 



' Wonders of Geology, vol. ii. p. 529. 



