12 



CITARA. 



In rocks of the Jurassic system several species have been dis- 

 covered. Saporta, 1 in his important contributions to the Jurassic 

 botany of France, institutes a new species, Chara Bleicheri, from 

 Oxfordian rocks at Cajase in the Department Lot. 



Heer 2 named a species, Chara Jaccardi, Hr., from the Purbeckian 

 of Villers-le-lac and other localities in the Canton Neuchatel ; this 

 species is also recorded by Saporta, 3 on the authority of Giradot, 

 from the same geological horizon in the neighbourhood of Pont 

 de la Choux. Another species, Chara Maillardi, Sap., has recently 

 been described from this district by Saporta, 4 but his figures show 

 the spiral markings of the encasing cells almost longitudinally 

 placed, and, indeed, the drawings are by no means convincing as 

 regards botanic affinity. 



Heer's species, Chara Jaccardi, Hr., is quoted by Schenk 5 from 

 beds which may be of Wealden age, at Locle in the Canton 

 Neuenburg. In Britain we have a reference by Phillips 6 to the 

 occurrence of Chara in the "Upper part of the Wealden deposits" 

 of Swanage Bay, Isle of Purbeck ; the same genus is included 

 in the list of Isle of Wight fossils in Bristow's Memoir 7 on the 

 Geology of that island, from a locality between Brixton and 

 Atherfield. 



So far as I am able to discover, no specific name has been applied 

 to these English Mesozoic Charas. In the Museum of Practical 

 Geology, Jermyn Street, there is a specimen showing a number of 

 hollow casts of the Isle of Wight Charas; these should probably be 

 included in the species Chara Knowltoni, sp. nov. A few of the 

 more clearly preserved casts show that there were about 10-12 

 almost horizontal lines on the surface of the oogonia. The casts 

 are somewhat longer and narrower than the impressions from 

 Ecclesbourne, but this may be due to the fact that the latter have 

 been more crushed, and have, therefore, an apparently greater 

 breadth. 



1 Pal. Franq. ser. ii. vol. i. p. 214, pi. ix. figs. 8 and 9. 



2 Urwelt, 1879, p. 176. 



3 Pal. Franc, ser. ii. vol. i. p. 216, pi. ix. figs. 12 and 13. 



4 Ibid. ii. vol. iv. p. 499, pi. Ixxii bis. 



6 Palaeontographica, vol. xix. p. 204, pi. xxv. fig. 1. 

 6 Quart. Journ. Geol. Soc. 1858, p. 46. 

 ' Mem. Geol. Surv. 1889, p. 258. 



