THE BRITISH SPECIES OF NAJAS 109 
peep ser rhinoceros, with some freshwater shells no longer living 
ection 8. Nude.—Both the male and female flowers without 
a sp. Sheaths markedly auricled. A single species generally 
distributed Rag the warmer parts of sas Old World. 
4, N. eramea Delile in Deser. Egypt. Hist. Nat. ii. 282, t. 50, 
Hg. 38 (1818) ; A. Br. in Journ. Bot. 1864, 278; C. Bailey, ib. 1884, 
250 ; Rendle, l.c, 424, t. 42, figs. 192-201. (PI. 408, figs. 10, 11.) 
Var. Delilei Magnus in Ber. Deutsch. Bot. Ges. i. 522 (1883) ; 
C. pee CA l.c. 805, t. 249. 
see 
Ma agnus found that the leaves of the Manchester specimens and 
also of some from Egypt and Syria did not have the row of thickened 
supporting cells (libriform cells) beneath the marginal epidermis, 
which is generally found in the species. He therefore separated 
them as var. Delilei, which, however, I have ventured to disregard, 
as the specimens conform to the type in every other character. 
lusion, it may be of interest to note that these four 
elements of our flor 
cold temperate cdnteainias European group, N. minor represents a 
somewhat more southern European set, and N. graminea a su 
tropical one, which at the present day is not endemic north of the 
Mediterranean basin. N. flewilis recalls a relation between the 
floras of North-west Europe and cold temperate North America 
ich is also suggested by Hriocaulon septangulare and Sisyrinchium 
paar he 
eae or Prats 408. 
— ree Allio . Portion of ae nat. size. 2. Single 
leaf, side view, X 3. wer in of leaf, front view, x 4, showing intra- 
vaginal scales. 4. Single tooth of leaf-margin, x ransverse section of 
stem, x 30; e, epidermis; s, central stele; between e and s is the cortex 
including a regular ring of intercellular bgee i. Male flower, x 30; 
8, 26 eg pe, pedicel; p, perianth ; a, = ed € Female flower, after fertili- 
12. 8. Seed, from a spec pan collected near Strassburg, x 12. 
9. Foi ier found by Mr. Reid at West Wittering, Sussex églaeshbond}; x 12. 
N. graminea Delile :—10. Seed, x 12. “11. Fossil seed from 
10, 
the plidatosaass of West Wittering (Reid), x 12. 
