304 R. F. Tomes— Corals of Crickley Bill 



Thamnaste^a Defranciana, Edw. et Haime, Pol. des Terr. Paleon. 



p. 110 (1851) ; Brit. Foss. Corals, pt. ii. p. 139, pi. 29, fig. 3 



and 4; Hist. Nat. Coral, torn, ii, p. 561. Astrma Defranciana, 



Mich. Icon. p. 9, pi. 2, fig. 1 (1840). 



In Michelin's figure the calices are more concentrically arranged 



than in any example I have met with. This appears to be a 



common species at Crickley. 



Thamnastr^a Terquemi, Edw. et Haime, Pal. des Terr. Paleon. 



p. 110 (1851) ; Brit. Foss. Coral, pt. ii. p. 140, pi. xxx. fig. 2 ; 



Hist. Nat. Coral, tom. ii. p. 579. 

 In most of the species from Crickley the basal portion is much 

 less symmetrical than in the figure given by Edwards and Haime 

 in their History of British Fossil Corals. In many examples the 

 epitheca is gone, and the whole of the inferior part of the corallum 

 has a more or less lobular form, and the outline of the calicular 

 surface has a corresponding degree of irregularity in its outline. 



Thamnastk^a Mettensis, Edw. and Haime, Brit. Foss. Corals, 

 pt. ii. p. 141, pi. xxx. fig. 3 ; E. de From., Introd. a I'Etude 

 Pol. p. 214. 

 This appears to be abundant at Crickley. 



Thamnastrjea Ltelli ? Edw. and Haime, Brit. Foss. Corals, pt. ii. 

 p. 118, pi. xxi. fig. 4. 



I refer a dendroid species from Crickley to this species with great 

 hesitation. Only one fragment has been examined, and it is so 

 very crystalline that no internal examination can be made. 



The columella appears to be rudimentary or wanting. The con- 

 fluent septo-costal rays are arranged transversely with the axis of 

 the branches, and the calices have a much clearer definition than 

 those of most of the species of Thamnastrcea. 



Thamnastr^a Fromenteli, n.s. 



Corallum thin and expanded. Above, somewhat convex with 

 irregular prominences ; below, concave. There is no epitheca. The 

 calicular surface has one central large calice, surrounded by many 

 small ones scattered irregularly about. They are small, superficial, 

 and indistinct, and a very few septa enter into their composition. 

 There is no columella. The septo-costal rays are very thin and 

 flexuous. They have a very distinctly radiate arrangement, and are 

 traceable from the large central calice outwards to the margin of 

 the corallum. The synapticulge are abundant, thicker than the septa 

 from which they spring, cuneiform, and their points meet in the 

 interseptal loculi. 



Diameter of the corallum 3|- inches ; height of the corallum in 

 the centre f inch. 



The large central calice and the slight development of the sur- 

 rounding small ones, with the radiate disposition of the very thin 

 septo-costal rays, will at once distinguish this species. 



One specimen only has been examined by me. It was obtained at 

 Crickley, but its position in the section was not ascertained. 



