R. F. Tomes — Some Cretaceous Machrporai-ia. 547 



good state of preservation to admit of satisfactory specific definition, 

 though it possesses characters which do not correspond with those 

 of any species of Asti-occenia which I have yet met with. 



IsASTK^A Eeuss[i]ana, M. Edw. & Haime. Hist. Nat. Corall. ii. 



p. 528. 



TTlophylUa crispa, Reuss. Denkschr. der Akad. der Wiss. "Wien, t. vii. p. 106, pi. ii. 



fig. 6, ISoi. (Not Milne Edwards and Haime). 



In the collection of Cretaceous Corals in the British Museum are 

 specimens of a coral, some of which have been obtained from Ather- 

 field, Isle of Wight, and others from Gosau. They are without 

 doubt specifically identical. Those from Gosau are labelled Isastrma 

 Beitssnna, Milne Edwards and Haime, which is the Ulophyllia crispa 

 of Eeuss. The specimens from Gosau differ however from the figure 

 given by Reuss in having their septa denticulated. The septa pass 

 quite uninterruptedly from one calice to another, though there is a 

 distinctly elevated line where the union of the calices takes place. 

 Gemmation occurs freely between, or just within the calices, as in 

 Isastrcea and Lafimcsnndra. The general aspect of this coral is very 

 much that of a Thamnastrcea, though on those parts of the corallum 

 where increase in the number of calices has been the result of recent 

 gemmation, a very Latimasandrine appearance is observable. 



A broken specimen shows well-marked dissepiments, and imper- 

 fectly developed pseudo-synapticulse, as in Thamnastrcea. In another 

 specimen there is an abundance of well-formed synapticulaa of a 

 similar kind. 



Leaving the identification and nomenclature of this somewhat 

 obscure species for future consideration, I must content myself with 

 observing of the Atherfield specimens that they, as well as the Gosau 

 examples, have both dissepiments and synapticulee. 



ISASTR^A NEOCOMIENSIS, Sp. nOV. 



A specimen of a coral referable to the genus Isastrcea forms part 

 of the British Museum collection, and was obtained from the 

 "Crackers beds" of the Upper Neocomian deposits of Atherfield, 

 Isle of Wight. It bears some general resemblance to the Isastrcea 

 profunda of Eeuss, but diff"ers from it in some important jjar- 

 ticulars. The calices are larger and shallower, and the septa of one 

 calice pass over the mural region and are continuous with those of 

 adjoining calices. So far as I can observe, this does not occur in the 

 species figured by Eeuss. The specimen is very broadly attached 

 (by the whole of its breadth) to a large specimen of Perna Ricordeana, 

 "D'Orbigny.^ The upper surface is convex, aud the outline consider- 

 ably resembles that of Isastrcea profunda. Around the outer margin 

 is a fringe of short but well-defined radiating costas, indicative of 

 further extension of the corallum over the surface of the shell. 

 The calices are distinctly polygonal, and where they are worn, the 

 dividing wall becomes very apparent. The septa are thin, regularly 



1 I am indebted to the kindness of Mr. R. BuUen Newton, F.G.S., for the 



determination of this shell, and for other information which has enabled me to give 

 the stratigraphical position of the coral here described. 



