Vol. 59.] HETERASTRJEA RHAETIC A m 403 



33. Description of a Species of Heterastr^ea from the Lower 

 RiiiETic of Gloucestershire. By Robert F. Tomes, Esq., 

 F.G.S. (Read May 13th, 1903.) 



1 have been favoured by Mr. L. Richardson, F.G.S., of Cheltenham, 

 with the loan of a small compound coral which he took from the 

 Lower Rhaetic Beds at Deerhurst (Gloucestershire). It is 

 undoubtedly a species of Heterastrcea, differing chiefly from the 

 several Liassic species in the small size of the corallum, and in the 

 small size of its calices. Mr. Richardson writes of its locality and 

 stratigraphical position as follows : — 



' The exposure where the coral was obtained is situated about three-quarters 

 of a mile east-south-east of Deerhurst Church, in a deeply-cut wheel-track. The 

 gate giving access to this track is almost opposite a barn which is situated less than 

 a quarter of a mile south-west of - The Folly.' The Upper Keuper red marls 

 constitute the subsoil of the field, and in the bank opposite the oak-tree the Tea- 

 green Marls are visible. In the winter of 1901 the following beds were revealed 

 by a very little excavating, but unfortunately the measurements were not taken ; 

 now the exposure is overgrown (August 1902) : — 



I. Upper ) n . , n _ , Thickness 



-r> > Greenish-yellow marls. . . 7 



JxiLETic. J J in inches. 



/'Shales, black. 



I Sandstones, hard, grey, calcareous; lamellibranchs 1 -. 



and coral ...., j 



II. Lower \ Shales, black. 



Kieetic. I Sandstone, Bone-Bed equivalent ; brown,micaceous, 1 . 



Schizodus { ?) , Acrodus minimus J 



^ Shales, firm, black. 



III. Upper J Tea-green Marls. 



Keuper. \ Eed Marls. 



' The nearest section where details of the above deposits can be obtained is at 



Coomb Hill, 1£ miles distant. Here the equivalent beds attain the following 



thickness : — 



Feet inches. 



/'Shales 1 



| Sandstone 2 



Lower Riletic. \ Shales 1 6 



j Sandstone, Bone-Bed 3 



I, Shales 2 



T ^ Tr f Tea-green Marls. 



Upper Keuper. { Eed * Marls/ 



From the foregoing it is evident that the coral occurs only a 

 very little way above the Bone-Bed, which there, as in many other 

 places, is a hard micaceous sandstone. It is specifically new, and 

 generically new to the Rhaetic formation, and, as I shall presently 

 show, has a very Jurassic relationship. I describe it as follows : — 



HeterastRsEA rhjetica, sp. nov. (figs. 1 & 2, p. 404). 



The corallum, as is so commonly the case with the compound corals 

 of the Pthaetic deposits, is small, and, so far as may be determined 

 Q. J. G. S. No. 235. 2 f 



