ESTHERIA STRIATA. 23 



2. ESTHERIA STRIATA, Munster, Sp. PL I, figS. 8 18. 



Sanguinolaria striata, Miinster and Goldfuss. 1826, Petref. Germanise, II, p. 280, pi. 159, 



fig. 19. 

 Cardiomorpha striata, De Koninck. 1842, Anim. Fossil. Ter. Carbonif. Belgique, p. 105, 



pi. H, fig. 9, a, b, c. 



Amongst the many fossil Bivalves of the Upper and Lower Carboniferous strata 

 there are several that more or less resemble small Unios ; and these have been subjected to 

 much change of nomenclature. One of the smallest and thinnest of these, usually repre- 

 sented by a mere impression, though occasionally a film of carbonate of lime has replaced 

 the shell, is Sanguinolaria striata of Miinster, from the Mountain-limestone series of 

 Regnitzlosau, near Hof, Bavaria. This was figured and described by Goldfuss ; and again 

 described and illustrated by De Koninck, who found it in the carbonaceous shales of the 

 Mountain-limestone of Vise, Belgium. Being able to recognise the umbonal area of the 

 closed valves, 1 De Koninck referred this fossil to his genus Cardiomorpha. 



I have seen numerous specimens of this fossil from several localities, and from different 

 horizons of the Carboniferous system of strata. Frequently they appear as conspicuous 

 black and shiny impressions on the dark-coloured shales ; sometimes they are obscure and 

 dull ; not unfrequently there are compressed casts of the bivalve ; occasionally the thin 

 shell has been converted into carbonate of lime ; or a rusty film may sometimes represent 

 the shell ; usually the two valves have been only slightly displaced (PI. T, fig. 9). The 

 very numerous concentric striae on these fossils is a striking feature ; also the absence of 

 relatively large, concentric, rounded ribs among these striae, though some of the latter 

 stand out stronger than the others, and at nearly regular distances apart (figs. 10, 12, 14). 

 Compared with those shells of small Aviculcs, Posidonomya, and Jnthracopfera, 2 that have 

 been wrinkled by pressure, the fossils under notice characteristically differ, by being less 

 subject than the former to coarse and irregular transverse wrinklings. In one instance (in 

 the shales from Lammerton, Berwickshire) we have some trace of structure in the film 

 representing the shells (figs. 16, 17) ; by this fact, together with the Estherian character of 

 the crowded striae (a feature not unusual in Estheria ; see PI. II, figs. 28 — 31 ; PI. Ill, figs. 

 6, 13, 23 ; PI. IV, figs. 1 — 3), I am induced to regard these little fossils as remains of 

 Estheria; and their tenuity, their gregariousness, and their association with fish-remains, 3 



1 De Koninck states that he saw the " hinge :" I doubt that he means the hinge itself (which is said 

 to be edentulous in Cardiomorpha, having only a narrow ligamental furrow, and an obscure internal 

 cartilage-groove) ; but he probably refers to the collocated umbos represented in his fig. 9 b. 



2 Mr. Salter's name for the MyaJince of his " Notes on the Fossils of the Iron-stones of South Wales," 

 'Geol. Surv. Mem.,' 1861. 



3 The occurrence of Bivalved Entomostracans in company with fish-remains is frequent in the fossil 

 state, and agrees with the known habits of these animals. The Entomostraca, like other Crustacea, act as 

 scavengers among dead molluscs and fishes ; and are an important article of food to many fishes. 



