GEOLOGICAL HISTORY OF THE CHAROPHYTA. 



83 



In several of the Middle and Upper Eocene beds in 

 tMs country Charophyte-fruits have been found rather 

 sparingly, but of these none is of a sufficiently distinct 

 type to call for notice. 



In the Headon beds, variously regarded by geologists 

 as Eocene and Oligocene, the remains are particularly 

 abundant, and a number of types of fruit are represented. 

 In the Lower Headon beds of Hordle Cliffs (Hants), alone, 

 as many as 16 more or less distinct forms were described 

 and figured by Clement Reid and myself (17); a few of 

 these are shown on Plate XLV, Figs. 11-18. One of 

 the large spherical type, C. Wrightii, Salter, occurs in 



Pie. 31. — Lagynophora, Staohe (after Staehe), from Lower Eocene. 

 a, L. libumica, St. ; b, L. symmetrica, St. 



inmaense quantity, two types of tuberculate fruit, a large 

 elUpsoid fruit which we referred to C. helicteres, Brongn., 

 and two very minute forms belonging almost certainly 

 to the genus Tolypella were present. Portions of stems 

 and branchlets were found in one of these beds in fair 

 quantity, also a few stem-nodes with the bases of branch- 

 lets. The cortex of some of the stems is of the single- 

 ranked type (Haplostichse), a type rare at the present 

 time, others of the common two-ranked type (Diplo- 

 stichse). I have not so far met with any of the three- 

 ranked type (almost equally common in living species) 

 among Eocene or Oligocene remains. 

 The Eocene and Oligocene of the Paris Basin are 



