ESTHERIA TENELLA. 



33 



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

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

 Estheria, found by Mr. Grossart, of Salsburg, near Holytown, Lanarkshire, in the 

 Coal-measures of Lanarkshire, Scotland. These are represented by shiny black impres- 

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

 39, and PL V, fig. 7). 



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

 (PL 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 (PL V, fig. 7) ; and in this they resemble those of E. tenella of Saxony (PL 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 Cypridm 

 appear to be closely allied to Cytlieropsis (?) iScoto-Burdigalcnsis 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. Coal-measures. 



22 Palace-craig ironstone (Black band). 



16 Estheria-shale 



15 Upper coal. 



Ell coal 



12 Main coal. 



Anthracosia acuta, Avicula, and Cytheropsis 



Scotoburdigalensis (?). 

 Anthracosia, Avicula, Spirorbis, Estheria. 



Gyr acanthus formosus, here and below. 



