106 Prof. T. Rupert Jones — Fossil Bkalved Entomostraca. 



C. Valdensis, Sow. Ovate and notched. 



— IcBvigata, Dunker. Ovate and notched. 



— oblonga, Eomer. Elongate-ovate and notched. 

 Dunker' s } — striatopunctata, Romer. Ovate and notched. 

 species. — J — granulosa, Sow. Ovate and notched. 



— ? tuberculata, Sow. Ovate and notched. 



— rostrata, Dunk. Ovate and strongly notched. 



— pinnceformis, Dunk. Long-ovate and notched. 



Forhes^s species. — None of tlie above-mentioned rough figures of 

 Forbes's Purbeck species (page 105) show the notch in any degree ; 

 but, being drawn from various points of view, they are, of course, 

 not satisfactory. In the Catalogue "Foss. Mus. Pract. GeoL, 1865, 

 above quoted (page 105), C. fasciculata, punctata, Purbeckensis, and 

 tuberculata are referred to Cypridea ; C. striatopunctata and Purbeck- 

 ensis being left with Cypris. 



§ 3. Bemarlcs on the Wealden Ostracoda. — Although these Entomo- 

 straca (Ostracoda) have been so generally referred to Cypris, it is 

 very doubtful if any of them belong to that genus ; in all proba- 

 bility, the majority belong rather to the Cytheridoe than to the 

 Cypridce. 



The classification of these kinds of Bivalved Entomostraca runs 

 thus.i 



OSTRACODA: PODOCOPA. 



1. Cyprid^. 2. Daewinellad^. 3. Cttherid^. 

 Cypris, Darwinella, Cythere, 



Candona, Cytheridea, 



etc. etc. 



Among the fossil Ostracoda of the Purbeck-Wealden strata there 

 are three kinds of Carapace-valves. 



A. — For the most part, the shape and structure of the valves are 

 such as occur more especially with Cythere and Cytheridea ; differing, 

 however, chiefly in the hingement, which wants the knurlings of the 

 latter and the distinct teeth of the former. In this respect they 

 agree best with the forms of " Cytherideis " figured in Monogr. 

 Tert. Entom., 1856, pi. 2, figs. 2, 3 ; but that is not a well-deter- 

 mined genus. 



B. — Some of the Wealden Ostracoda are characterized by having 

 an antero-ve-ntral notch, more or less pronounced, especially in the 

 more ovate forms of C. Valdensis ; see Monogr. Fossil Estheriaj 

 (Pal. Soc), 1862, Appendix, p. 127, pi. 5, figs. 26 and 28. The 

 presence of this feature induced M. J. Bosquet,^ of Maestricht, to 

 suggest that such species should be referred to a separate genus 

 — Cypridea. 



As a matter of convenience, it will be well to use this name, 

 although as yet we do not understand the physiological value of the 

 feature in question, which is certainly very variable in development. 

 It may be concerned with the play of the lower antennae ; but it is 



1 Brady, Crosskey, and Robertson's Monogr. Brit. Post-Tertiary Entom., Pal. 

 Soc. 1874, p. 110, etc. 



2 " Description des Entomostraces fossiles des Terrains tertiaires de la France et 

 de la Belgique," Mem. cour. Acad. Roy. Belg., vol. xxiv. 1852 ; page 47 of the 

 separate memoir. 



