22 CRETACEOUS ENTOMOSTRACA. 



PL II, fig. 1 = PI. IV (1849), fig. 11 a. Length 1-05 ; height -55 mm. 

 PL II, fig. 2 = PL IV „ fig. 11 c. „ 1-16 ; thickness '82 mm. 



PL II, fig. 3 = PL IV 

 PL II, fig. 4= PL IV 

 PL II, fig. 5 = PL IV 

 PL II, fig. 6 = PL IV 

 PL II, fig. 7 = PL IV 



fig. 11^. „ I'O; „ -55 „ 



fig. lie. Height -55; „ -568 „ 



fig. 11/. Length 1*02 ; height -568 mm. 

 fig. 11^. „ -82; „ -47 „ 



fig. 11 /. „ '91 ; thickness "41 mm. 



PL II, figs. 15 & 16 I = PL IV (1849), figs. 11 h, h'. Young. Length -72 ; 



PL IV, figs. 7 & 8 ) height '35 ; thickness -27 mm. 



This common and strongly marked species is subject to many modifications of 

 individual growth and varietal development. 



Dr. A. E. von Reuss having shown the badly figured Bohemian specimens to 

 Mr. J. Bosquet, of Maastricht, the latter decided (1854) that G. ornatissima and 

 C. ciliata are the same. 



Fig. 11/ of the old PL IV (PL II, fig. 5) was made, by optical illusion, to 

 show its beautiful reticulate pattern like small tesselated blocks. This punctate 

 ornament is obscured and mostly obliterated by the exaggerated growth of the 

 mesh-walls in old and large individuals,' but many specimens of smaller growth 

 preserve it very well. 



PL II, figs. 15 and 16, and PL IV, figs. 7 and 8, represent the young 

 G. ornatissima, differing from the adult forms in its subtriangular, instead of 

 oblong, outline ; and in its posterior region not having the relative thickness of 

 the adult. An apparent subangular elevation of the coarsely punctate, but 

 relatively smooth, surface has been exaggerated in both fig. 11 h and fig. 15 (see 

 PL IV, figs. 7 and 8). The centre bears a definite tubercle, the anterior hinge is 

 strongly marked, the dorsal edge is thickened and rough, the front and hind 

 margins are strongly depressed, and the hind margin is angular. In these 

 features it has the essential characters of G. ornatissima. 



Rare : fig. 15 from the Grault of Folkestone ; fig. 16 from the Chalk-marl (?) of 

 Charing. 



Localities. — GhalJc, Gravesend and South-east England ; Ghalk-rock, Dunstable ; 

 Chalh-marl, Dover ; Betritus, Charing ; Gault, Folkestone, Leacon Hill, and 

 Godstone ; Greensand, Warminster and Ventnor. 



Foreign. — Ghalh-formation, Bohemia, &c. See Reuss, ' Elbthalgeb.,' p. 147. 



^ As also occurs with similar ornament in other Ostracoda, aa Oythereis Bowerhanhii, Gythero- 

 pteron concentricum, &c. 



