82 CARBONIFEROUS ENTOMOSTRACA. 



IV. CYPRIDELLA, Be Koninck, 1844. 



Cxv^&lDl^i^i^., De Koninck, 1841, 1844. 

 Cypridella, Be Koninck, 1844. 



— Jones and Kirkby, 1 863. 



Carapace subovate, with either attenuate or subquadrate hind quarters ; notched in 

 front, with different degrees of beak or hood ; tuberculate in various degrees, and im- 

 pressed with a transverse dorsal sulcus behind the main pair of tubercles. Both the 

 original subquadrate Cypridella cruciata of De Koninck, with one large tubercle on 

 either valve, and his ovate Cypridina Edwardsiana^ with more tubercles, are compre- 

 hended in this revised genus on account of intermediate alliances. 



In the following arrangement of species we pass from the ovate to the subquadrate 

 forms (Nos. 1 — 5), and then take a somewhat abnormal species that looks towards the 

 next group {Cyprellcs). 



Of these Cypridella Koninckiana and C. ohsoleta are apiculate and indented behind ; 

 the others had posterior spines. 



1 . Cypridella Edwardsiana (Z>e Koninck). Plate IV, figs. 4 a — c ; PI. V, figs. 1 1 a — c. 



Cypridina Edwardsiana, Be Kon., 1841. Mem. Acad. Roy. Belg., vol. xiv, p. 17, 



fig. 9. 



— _ _ 1843. InD'Omalius'Preciselem. Geol.,p.515. 



— — — 1844. Descript. Anim. foss. Terr. Carb. Bel- 



gique, p. 287, pi. lii, fig. 2 a — d. 

 Cythere — Buponf, 1863. Bullet. Acad. Roy. Belg., ser. 2me, vol. xv, 



p. 110. 

 Cypridella — Jones and Kirkby, \864. Canad. N. Geo!., June, 1864, 



p. 237 ; N. Jahrb., f. 1864, 

 p. 54. 



Carapace-valves gibbose, tuberculate ; subovate in profile, nearly subtrigonal ; acute 

 behind, broad, and notched in front. Raised into a large subcentral tubercle (in the antero- 

 dorsal region), with two or more smaller knobs, above and below. Impressed with a 

 dorsal or nuchal sulcus, passing from the back with an oblique curve across the centre, 

 and dying out below. 



The notch is obscure within the broad sinus of the front in the few specimens we 



