Fossil Entomostraca from Brazil. 



197 



that at Pojuca tunnel, which traverses " Cretaceous " strata near 

 Tertiary hills (view given at p. 371). In the cutting at the eastern 

 entrance of the tunnel horizontal Tertiary (?) beds of soft brown 

 sandstone occur, and in them " a bed, fifteen centimetres in thick- 

 ness, of a yellow clay, decomposed shale (?), in which I have found 

 a few Estherians"' (p. 371). The laminated blue-grey sandstone 

 of the tunnel contained fish-remains and fragments of plants. 



Summary of the occurrences of Fossil Entomostraca, etc., collected 

 by Joseph Mawson, Esq., F.G.S., from cuttings on the Bahia and 

 San Francisco Eailroad, Brazil, 1888. 



Estheri'ina Bresiliensis, 

 gen. et sp. no v. 



expansa ,, 



astartoides , , 



Estheria Mawsoni,^ sp. 

 nov. 



: var.- 



Cyprididae^ 



Anodonta Harttii, 

 White ... 



Maivsoni, 



White ... 



sp 



Area, sp 



At Kilometres from Bahia. 

 3-85, 4, 5— — 



12-13 73 74 82 83 — 

 12-13 73 — — — 84-5 



— 83 — 



12-13 



; 



Erit. Mus. Nos. 



13, 37, 371, 372. 



L. 304-4. 



L. 304-3, L. 304-4, 



L. 304-5. 

 (No. 31, L. 304, 

 ) L. 304, L. 304-1, 

 1 L. 304-2, L. 304-4, 

 ( 1.466,1.466,6-10. 



L, 304-3. 



L. 304. 



§ II. EsTHEKiiNA, genus novum. 



An Estherian carapace, the valves of which are not equally 

 gibbose throughout, but more convex for a limited area in the 

 urabonal region than lower down in the ventral region. Lines 

 of growth are strongly marked on the convex portion ; and are 

 feeble, but numerous, on the flat marginal area, which varies in 

 expansion in different species. 



Three forms are observed in the Brazilian series under notice ; 

 and two published fossil forms seem to come into'the same genus. 



The zoological value of the umbonal convexity may be differently 

 estimated from different points of view. It certainly seems to repre- 

 sent an exuberant growth of the early, compared with the later, 

 parts of the animal and its valves. Although neither the " proto- 

 couch " in Gasteropoda and Cephalopoda, nor the " prodissoconch " 

 in Lamellibranchiata, constitutes a classificatory feature in their 

 genera or even their species, yet the persistent enlargement of the 

 early part of the valves in bivalved Estherian Entomostraca is peculiar, 

 and may be conveniently recognized as distinctive of a genus, or at 

 least of a subgenus, in this group of Phyllopoda. 



1 It is probable that E. Mawsoni (to be described subsequently) was Feen by 

 Mr. Hartt at Pitanga and Pojuca. 



^ To be described in another communication. 



