Fossil Entomostraca from Brazil. 201 



(brepbic) form as in tbe post-larval (neanic) stages. Looking at 

 the fossils above mentioned in this light, it seems that E. Bresiliensis 

 shows valves of advanced adult growth (having nearly 40 lines of 

 growth) with a prodissoconcbal protuberance usually little less than 

 half the size of the valve. The other two forms (Freysteini and 

 limhata) are also adults (with about 30 lines of growth), and each 

 exhibits an umbonal swelling, having an area little less than that 

 of the whole valve. 



This umbonal swelling does not constitute merely a specific 

 difference ; it points in all probability to subgeneric or even to 

 generic distinction, as much as the cbaractei'istio features of the 

 Triassic Estheriella. 



Although, without indications of the limbs and soft parts, its 

 separation from Estheria can be only provisional, yet it seems to be 

 expedient and useful to recognize this hump-backed form as typical 

 of a genus, with the name of JEstheriina. 



§ VI. 4, ESTHERIINA EXPANSA, Sp. nOV. 

 PLATE VIII, Figs. 6«, 66. 



A small, obliquely oval-oblong, flattened, yellowish, and filmy 

 valve exhibiting two different areas of surface ; namely, a small 

 subtriangular portion near the umbonal end, bearing a few strong 

 concentric ridgelets, and a larger expanded flattened part of the 

 valve, smooth and shining, with traces of concentric markings and 

 irregular wrinklings. A faint reticulation of irregularly subquadrate 

 meshes is discernible between the riblets on the umbonal region 

 (Fig;. 66). 



Size. — 7-6 X 5 mm. The umbonal convexity measures 

 3-0 X 1'6 mm. 



In the usual soft light-brownish shale, from a cutting at kilometre 

 83 from Bahia, between Pojuca and San Thiago. 



This is evidently an Estheri'ina, but different from both E. Bresili- 

 ensis (Figs. 1-5) and E. astartoides (Figs. 7 and 8), agreeing 

 more with the former than the latter. It is interesting to find the 

 same genus [Estheri'ina) represented at localities fifty miles apart, 

 at 4-5 kilom. (Pedra Furada) and at 83 kilom,, from Bahia (near 

 Pojuca). 



§ VIT. 5, Estheri'ina astartoides, sp. nov. 

 PLATE VIII, Figs. 7, 8a, 8b. 



A small, semicircular, somewhat gibbose carapace ; swollen, thick, 

 and marked with strong concentric ridgelets on the moiety of each 

 valve near the umbo, and flattened into a broad, marginal area 

 on the free borders, with faint concentric lines. 



A specimen (Fig. 7) that has preserved its normal form measures 

 3 X 2-6 mm., and the umbonal convexity 2 x 15 mm. 



Another specimen (Fig. 8a) measuring 3x26 mm. is subovate, 

 having probably been modified by pressure. The convex part has 

 lost its distinctness from the flatter portion for the same reason. 

 Feeble traces of some transverse lineation in the larger concentric 



