26 CRETACEOUS ENTOMOSTRACA. 



6. CiTHEREis TUBEROSA, sp. nov. Plate III, figs. 2 and 3. 



Length "7 ; height '36 ; thickness '36 mm. 



Suboblong, upper and lower margins nearly straight, but the dorsal is roughly 

 tuberculate ; rounded and denticulate in front ; depressed, narrow, and jagged 

 behind the raised body of the valve, which bears the unequal elevations of the 

 strong subcentral boss and swollen posterior corners ; the latter are very lumpy 

 in some, but more angular in other individuals. Edge view subsagittate. 



Locality. — Chalk, Horstead, Norfolk. 



6*. Cytheeeis tubeeosa, sp. nov., var. symmetrica, nov. (or young). Plate III, 



fig. 1. 



Length "52 ; height '26 mm. 



Small, subquadrate ; neatly rounded, rimmed, and slightly denticulate in front ; 

 depressed, angular, and sharply toothed behind ; straight above and below ; place 

 of the anterior hinge faintly marked. Body of the valve bearing a strong 

 subcentral boss, two broad, subequal, sharp posterior angles, and two smaller 

 equal angular tubercles, one in the middle of the dorsal and one opposite on the 

 ventral edge. This is possibly the young of the foregoing. 



Locality. — Chalk, Horstead, Norfolk. 



7. Cytheeeis Icenica, sp. nov. Plate I, figs. 37 — 39. 



Cytheeeis macbophthalma, Jones (uot Bosquet). Monogr. Entom. Cret., 1849, 



p. 17, pi. ii, figs. 8 a, b, b', 

 b", b'". 



Cttheee macbophthalma, Jones (uot Bosquet). Geol. Mag., 1870, pp. 75, 77. 



Length '55 ; height '33 ; thickness '33 mm. 



The description of the two odd English valves (from the Chalk of Norwich) 

 given in 1849 holds good, but certainly differs from that given by M. Bosquet of 

 his equally rare specimens from the Maastricht Chalk of Sichen, as intimated by 

 him in the ' Mem. Comm. geol. Neerlande, 1854, p. 97. The difference is chiefly 

 in the greater height (breadth) and more obovate shape of the English form. 

 We may here notice that Marsson's Cy there chelodon (from the Chalk of Riigen, 

 ' Mitth. Neu-Vorpommern, &c.,' 1880, p. 43, pi. iii, figs. 13 a—f), is an ally of 

 this species. 



