Prof. T. Rupert Jones — South Wales Entomostraca. 219 



The casts also show somo faint signs of the wrinkles, together with 

 reticuhitiou avoimJ the raised circle of tlicir " muscle-spots." On tho 

 outside shell the "muscle-spot" a^ipcars only as a small obscuro 

 patch of darkish tint. 



§ 4. Carbonia (?), sp. (PI. IX., Fig. 5).— There are at least two 

 specimens of a large Oythoroid species, not well preserved, casts only 

 remaining, which deserve notice. Tlie larger one, which is best pre- 

 served, is hero figured ; but it is hazardous to fix its generic relation- 

 ship. Tho cast is faintly reticulate. 



§ 5. Lcaia Leidyi, Jones, Monograph of the Fossil Esthence, 1862, 

 Appendix, p. 115, &c. (PL IX.,Figs. 11-14). Messrs. Meek and Worthen 

 have shown that in somo specimens of Leaia (L. tricarinata, M. and 

 W., Ecport Geol. Survey Illinois, 1869, p. 540, &c.) there is evidently 

 a third (dorsal) carina on each valve, bounding a dorsal depression 

 (their "lanceolate false area"), along the bottom of which is the 

 hinge-line. In compressed specimens this is not distinguishable, 

 and whether or no it is present in all (as it well may be) they leave 

 an open question (p. 543). We may add that, thanks to our artist, 

 Mr. George West, we can now point out that Leaia had the usual 

 Crustacean ornament of reticulation; so common in Entomostraca, 

 especially in Estheria. As this character may have been present 

 in other Leaice, but destroyed by pressure and change, we cannot 

 use it as a specific character in this case ; and as to outline and 

 proportions, the many individuals on the shales found by Mr. W. 

 Adams, in South Wales, comprise all the forms yet figured by Lea, 

 Dawson (" Acadian Geol.," 1868, p. 256), Meek and Worthen, and 

 myself, and may be due to differences in age or sex, or con- 

 ditions of preservation. Perhaps we may say the same of Geinitz's 

 L. Bcentscliiana, from the Lower Permian beds near Neunkirchen, 

 "N. Jahrb.," 1864, p. 657. It is, of course, probable that different 

 " species " did exist, and are represented among the several forms 

 found in distant countries ; but we still wait for further and decided 

 evidences of specific characterization. 



§ 6. DapJinioid (?) Entomostraca. — On one of the slabs of bitu- 

 minous shale from South Wales is a layer of small black bodies, 

 acute-ovate and vv^rinkled, that were at first thought to be spore- 

 cases, but Mr. Carruthers cannot discern any plant character in 

 them, and suggests that they may be small thin Entomostracau 

 valves, analogous to those of the modern Daphnia and their allies. 

 They show indications of being bivalved, and have one end more 

 pointed than the other. They are also boldly marked with longitu- 

 dinal and inosculating wrinkles (probably lines of breakage from 

 compression), which distantly imitate the wrinkles on a collapsed 

 seed-vessel, or even the ornament on some seeds ; but the eminent 

 Botanist just mentioned cannot find in them sufficient evidence for a 

 place among vegetable organisms. Mr. Carruthers has reminded 

 me that the vv^oodcuts (figs. 10 and 11) at pages 39 and 40 of 

 Emmons's "American Geology," Part vi., 1859, closely resemble 

 these crushed organisms, and are there referred to Entomostraca. 



