18 
THE ENTOMOSTRACA OF 
No. 4. Cythereis triplicata, Roemer. Tab. Ill, fig. 9 a — h . 
Cytherina triplicata, Roemer. 1840. Verstein. Kreidebirg, p. 104, n. 3, pi. xvi, fig. 16. 
Cythere auriculata, Cornuel. 1846. Mem. Soc. Geol. de France, sec. ser., tom. i, sec. part., 
p. 200, n. 3, pi. viii, figs. 14-16. 
INCH. 
Length, -Jg- Gault, FoUcstone and Leacon Hill. 
Height, Detritus, Charing. 
Thickness, ^ Chalk, South-East England. 
Hils-clay, North Germany {Reenter'). 
Inferior Greensand, France {Cornuel). 
Carapace ovate. Valves strongly convex, especially on ventral half ; very finely 
punctate and hairy ; bearing three longitudinal, convex ridges, three fourths the 
length of the shell, barely meeting posteriorly, free anteriorly ; the lowest ridge the 
longest, the middle one the shortest ; the dorsal and the central ridge smooth and 
not punctated, the ventral ridge coarsely pitted. Central tubercle large, forming the 
anterior extremity of the middle ridge. Anterior extremite/ of the valve semicircular, 
shelving abruptly to a flat lip, extending across the valve, and occupying a fourth of 
its length. Posterior extremity shelving, contracted, subacute. 
Dorsal and ventral aspects subovate ; the latter marked with three or four coarse, 
longitudinal wrinkles. Anterior aspect triangular. 
This species occurs in the Gault, the Charing Detritus, and the Chalk ; but is not 
at all plentiful. M. Roemer describes it as occurring in the Hils-clay of Hilse. In 
the Bohemian Chalk-marl there is a nearly allied form, C. semiplicata, Reuss (Op. cit. 
p. 104, pi. xxiv, fig. 16), and there are others in the Maestricht Chalk, viz. C. Porsteriana, 
Bosq. (Op. cit. pi. ii, fig. 4), C. pulchella, Bosq. (Op. cit., pi. ii, fig. 5), and C. elegans, 
Bosq. (Op. cit., pi. hi, fig. 1) ; another of very similar characters is found in the Forest- 
marble. 
No. 5. Cythereis quadril.atera, Roemer. Tabs. Ill and IV, fig. 10 a—f. 
Cytherina auADRiLATEUA, Roemer. 1840. Verstein. Kreideb. p. 105. n. 7, pi. xvi, fig. 19. 
— ORNATissiMA, bis, Reuss. 1845. Verst. Bobm. Kreid. p. 104, n. 12, pi. xxiv, 
fig. 18. 
Cythere Harp a, Cornuel. 1846. Mem. Soc. Geol. de France, sec. ser., tom. i, sec. part., p. 199, 
n. 2, pi. viii, fig. 13. 
YOUNG. IMMATURE. ADULT. 
INCH. INCH. INCH. INCH. 
Length, 
1 
42 
1 
35 
1 
25 
1 
2 0 
Height, 
1 
100 
1 
5 0 
1 
5 0 
1 
4'D' 
Thickness, 
1 
100 
"1 
5 0 
1 
5 0 
1 
4 0 
Gault, Folkstone and Leacon Hill. 
Detritus, Charing. 
Chalk, South-East England. 
Upper Oolite, Dorsetshire. 
Inf. Greensand, France {Cornuel). 
Chalk-marl and Chalk, Bohemia 
{Reuss). 
Chalk, North Germany {Roemer). 
Chalk, Weissbohla, Saxony. 
Carapace irregularly oblong. Valve depressed, smooth, shining, hairy. Anterior 
extremity obliquely rounded, having a flattened lip, longest in young individuals, with 
