ESTHERIA ELLIPTICA. 105 



Dr. Diinker adds : — " Another very similar, but doubtful, form occurs in the lower 

 calcareous and marly portion of the Wealden, near the Serpulite-beds, on the Siintel." 



In the Rev. J. H. Austen's * Guide to the Geology of the Isle of Purbeck,' 1852, 

 p. 14, one of the Lower Purbeck beds (No. 128) is said to contain EsthericB ;^ but these 

 are impressions of Archaeoniscal fragments, as the Rev. O. Eisher first suggested. 



Dr. Eitton and Mr. J. de C. Sowerby have noticed the English form of Estheria 

 eUiptica, under the name of Cyclas suhquadrata (' Geol. Trans.' 2nd ser., vol. iv. p. 177, and 

 p. 345, pi. 21, fig. 8), as occurring at two localities near Hastings. Dr. Dunker did not 

 observe this when describing his specimens ; and he independently gave the name " suh- 

 quadrata" to one of the forms he met with in Hanover. As the large forms of E. eUiptica 

 are typical of the species, and as the smaller and subquadrate individuals are either im- 

 mature or varietal, both names are not required ; but the type retains the appellation given 

 by Dunker, and the twice-given name suhquadrata belongs to the small form found both in 

 Germany (with the type) and in England. In Dr. Fitton's memoir, " On the Strata below 

 the Chalk," he. cit., pi. 21, fig. 8, we have a sketch of eight specimens of natural size, 

 on a piece of shale, and an enlarged view of an individual, described by Mr. J. de C. 

 Sowerby, at p. 345 of that memoir, as " Cyclas suhquadrata .- transversely oblong, with 

 straight sides ; strongly marked with hnes of growth ; fiat (perhaps from pressure). 

 Eound at St. Leonard's, Sussex." The locality would more coxvecilj he Bulverhithe ; 

 for at p. 177 C. suhquadrata is said to occur in the "Hastings sand, East Clifi", Hastings, 

 in soft, fine, sandy clay, not effervescent; also cliff west of St. Leonard's ;" and at the 

 first chff (Bulverhithe) in this direction they are found in plenty. 



The English Wealden Estheriee that I have seen are from that portion of the formation 

 known as the " Hastings Sand," and from two or three horizons in that series. 



1. Erom the neighbourhood of Tunbridge Wells. This specimen, given to me by the 

 late Dr. Mantell, is a hard, grey, fine-grained, sandy, micaceous shale or mud-stone, 

 retaining casts of Cyrena and small Paludina on one bed-plane, and Estheria on another 

 (about half an inch apart). The valves are represented by dark-brown films, mostly 

 crumpled, and by impressions. A trace of the original bar-ornament (PI. Ill, fig. 24) 

 can here and there be detected. 



The Hastings Sand of the neighbourhood of Tunbridge Wells has been well described 

 by Mr. E. Drew, E.G.S., in the ' Quart. Journ. Geol. Soc.,' vol. xvii, p. 276, &c. ; but I 

 cannot indicate the stratum from which Dr. Mantell obtained the specimen under notice. 



2. Erom the East Cliff, near Hastings ; collected and communicated by Mr. S. H. 

 Beckles, E.R.S., E.G.S. This is a hard, hght-brown, fine-grained, micaceous, sandy shale, 

 with numerous brown, crushed carapaces on a bed-plane, and with Cyprida scattered in 

 the matrix. Mr. Beckles informs me that this specimen was taken from the lower part 



1 The Rev. 0. Fisher, F.G.S., informs me that he fouud these specimens and showerl them to Prof. 

 E. Forbes (then at work on the Purbeck beds), who thought they might be Estherice. It was upon this 

 information that they were noted in his pamphlet by the Rev. Mr. Austen, who has lately shown them to me. 



14 



