Fossil Entomostraca from Brazil. 199 



ont nnder pressure, but not to the fullest extent. In their height, 

 modified by squeeze, these valves are much less than that of Fig. 1. 



Size,. — Valve, length 7 mm., height 2*6 mm. ; umbonal convexity, 

 length 2'8mm., height 1 4 mm. 



There are several other specimens of these black and shining 

 valves of approximately similar shapes, but more or less altered by 

 pressure, both scattered on the dark-coloured shale from " kilom. 4," 

 and lying thickly together in the dark and almost bituminous shale 

 from "kilom. 5." 



Bemarlis on some Allied Forms. — A somewhat similar feature 

 (namely, the umbonal convexity) occurs in H. B. Geinitz's 

 " Estheria Freyst'eiyii," from the Coal-measures of Saxony. A large 

 portion of the valve is raised in a persistent convexity near the 

 umbo (10 mm. long and 8 mm. high, in a valve 12 X 10 mm.), 

 leaving a flattened marginal area, much narrower than in the 

 Brazilian specimens under notice. There is also some indication 

 of this characteristic feature in Goldenberg's " Estheria limbata.'^ 

 For the purpose of comparison, concise descriptions of these two 

 forms are here given. 



§ IV. 2, EsTHERiiNA Freysteini (Goinitz), 1855 and 1876. 

 PLATE VIII, Figs.' 9, 10. 



Cardinia Freysteini, Geinitz, Versteinerungen der Steinkohlen- 

 formation in Sachsen, 1855, p. 2, pi. xxxv, figs. 7a, 7a. Estheria 

 Freysteini, Geinitz, Sitzungs-Berichte der naturwissensch. Gesell- 

 schaft Isis in Dresden, Jahrgang 1879, p. 10, pi. i, figs. 2a, 2a. 



Each of these has a straight hinge-line, and a large portion of 

 the valve near the umbo is very much more convex than the rest 

 of the surface. 



The specimens of which figs. 7a, 7a were given in 1855 were 

 from the Coal-shale of the Scherbenkohlflotze of Oberhohndorf, 

 near Zwickau. Of these there were a few examples measuring 

 13x11 nim. 



That one figured as 7a appears to measure — 



Size. — Valve, length 15 mm., height 13 mm. ; umbonal convexity, 

 length 11 mm., height 9 mm. 



Thei-e are 19 or 20 strong concentric ridges on the convex part, 

 and 9 or 10 delicate lines traceable on the flat part of the valve. 



The " EsthericB " figured in 1879, figs. 2a, 2a, came from the 

 Upper Coal-formation, Carl-Schachte, near Lugau, Saxony ; and 

 fig. 2a appears to measure — 



Size. — Valve, length 12 mm., height lOmra. ; umbonal convexity, 

 length 11 mm., height 9 mm. 



In some pencil drawings of the same species, kindly supplied by 

 Dr. H. B. Geinitz, the measurements are — 



Size. — Valve, length 12 mm., height 10 mm. ; umbonal convexity, 

 length 10 mm., height 8 mm. 



There are, it seems, 12 or 13 concentric riblets on the valve ; and, 

 of these, 6 or 7, on the postero-dorsal area, appear to be delicate 

 lines continuous with some of the coarser ridges of the convexity. 



