ESTHERIA TENELLA. 



33 



5. Intermediate in size between those of the ironstone and those of the shale of the 

 Eour-feet Coal, above mentioned, and better preserved, are some specimens of a similar 

 ■Esiheria, found by Mr. Grossart, of Salsbm'g, near Holytown, Lanarkshire, in the 

 Coal-measm'es of Lanarkshire, Scotland. These are represented by shiny black impres- 

 sions, readily affording traces of a delicately sculptured reticulate ornament (PI. II, fig- 

 39, and PI. V, fig. 7). 



Mr. Grossart's specimens show the concentric ridges distinctly, twelve and upwards 

 (PI. II, fig. 39) ; as usual in adult Estheria, the ridges are crowded towards the ventral 

 border. The interspaces bear a faint dotting, attributable to a delicate and minute reticula- 

 tion (PI. V, fig. 7); and in this they resemble those of E. tenella oi Saxony (PI. I, 

 figs. 26, 27), to which also the Estheria under notice has a close resemblance in general 

 form, except that it is not quite so oblong. 



Of E. tenella from Lanarkshire, I have seen about a dozen individuals in a black shale. 

 The specimens were discovered, and kindly submitted to my examination, by Mr. Grossart, 

 who has also shown me several other Entomostraca, which he has discovered in the Coal- 

 measures of that district. 



In the 'Geologist,' vol. ii, 1859, p. 466, Mr. Davidson gives a tabular view of the 

 Carboniferous Strata of the Clydesdale Coal-field (Lanarkshire). These are divisible into 

 four great groups : 1. The Upper Coal-measures; 2. The Upper Limestone series; 

 3. The Lower Coal-measures ; and 4. The Lower Limestone series. The Upper Coal- 

 measures of Lanarkshire, in one band of which Estheria have been found by Mr. Grossart, 

 is said to have, in some places, a thickness of about 159 fathoms. It contains eleven 

 seams of workable coal, and numerous smaller seams; the "Ell Coal" one of the best 

 known, is situated towards the top of the series. Besides the coals, this series consists of 

 sandstones^ for the most part white, or white with dark streaks, of fire-clays and shales, a 

 bed of so-called freshwater limestone, and a few important bands of ironstone. 



Mr. Grossart has sent me a list of the more important beds of this Upper Coal-measure 

 series. The " Ell Coal " is taken as a recognisable horizon, and the distances above and 

 below that coal are indicated in the table for the chief coals, shales, and ironstone. I have 

 inserted the names of the Entomostraca with their respective beds. Most of the Cypridce 

 appear to be closely allied to Cytlteropsis (?) Scoto-Burdiyalensis or C. suberecta ; but I 

 have not yet been able to determine exactly the species, of which there appear to be about 

 four or five. 



Coal-measures of Lanarkshire. 



Fathoms. Upper Coai.-measures. 



22 Palace-craig ironstone (Black band). 



16 Estheria-shale 



15 Upper coal. 



U Ell coal 



12 Main coal. 



Anthracosia acuta, Avicula, and Cytheropsis 



Scotoburdigalensis (?). 

 Anthracosia, Avicula, Spirorhis, Estheria. 



Gyraeanthus formosus, here and below. 



5 



