16 CRETACEOUS ENTOMOSTRACA. 



at Brill, both as to sliape and the punctation of the surface, that it is probably 

 right to refer them both to the same species. 



The recent Gytherideis ? ptdchra, Gr. S. Brady, 'Trans. Zool. Soc.,' vol. v, 1866, 

 p. 368, pi. Iviii, figs. 3 a — c (a left valve, from the Arctic Sea), has a somewhat 

 similar but more ovate shape, and a coarse linear punctation on a part of the 

 surface ; but its convexity lessens forwards, and its hingement is not that of a 

 true Gythere. 



§ II. Oblong forms, with three elevations or slight swellings. 



3. Cythere Harrisiana, Jones. Plate I, figs. 47 — 52. 



Cttheeeis intereupta, Jones (not Bosquet). Monogr, Eatom. Cret., 1849, p. 16, 



pi. ii, figs. 6 a — h. 

 Cytheee Haeeisiana, Jones. Greol. Mag., 1870, pp. 75, 76. 



— — Jones and Sherhorn. Greol. Mag., 1887, p. 452, woodcut, 



fig. 1 ; and Suppl. Monogr. Tert. 

 Entom., 1889, p. 24, woodcut, fig. 2. 



Fig. 47. Length -m ; height '33 mm. 



Figs. 48 and 49. Length -72; height '44 mm. 



Fig. 50. ,, '66; thickness "33 mm. 



Fig. 51. „ -61; „ -305 „ 



Fig. 52. Height -44 ; „ -305 „ 



The many specimens representing this sub-oblong Cythere have several varietal 

 features. Fig. 47 (formerly fig. 6 a) was taken as the type, and is probably a 

 male individual. Figs. 48, 50, 51 (formerly 6 b, 6 e, 6f), described as var. a, may 

 be regarded as the larger and somewhat coarser female carapace. Figs. 49 and 

 52 (formerly figs. 6 c and 6 g), treated as var. /3, belong probably to females less 

 coarse in structure. The body of the valve above the suddenly depressed hinder 

 margin is full, and often subtruncate, with the two angles somewhat swollen. 



PI. I, fig. 43 (var. S, setosa) evidently matches fig. 48 in shape ; and figs. 44 

 and 45 (var. S) have some features of their own in their relative shortness, the low 

 ridge along the middle of the valve (or, rather, the depressions on each side of the 

 middle), and the strong pinching in of the posterior margin.^ The prickles on the 

 angles of the hinder quarter of fig. 45 are present also in fig. 51, and slight in fig. 48. 

 Figs. 43 — 45 show small scattered spinules. Figs. 47 — 52 are more or less coarsely 

 punctate,*^ the pits being in lines, mostly longitudinal. The var. y (' Monogr.,' 



' Figs. 43—45 are magnified more than figs. 47 — 52, as 25 : 18. 



2 The coarse pittings were exaggerated on figs. 6 a and 6 b into tuberculate roughness. 



