Preliminary Report on the Purbech Characese. 255- 



each process is connected by a pore at the base, the central one or more of 

 the pores being larger than the lateral; the processes are more or less 

 elongated, swelling upwards, and are round-ended. Though occupying the 

 same position, these processes are evidently not analogous to the spine-cells 

 of living Chareee, as they are not separate cells. 



The head gives rise to a whorl of six branchlets, which are produced from 

 the broadest part. Similar whorls occur on some (probably the upper) 

 spindles. 



The branchlets (fig. 3), which are spreading or ascending, are composed of 

 a single tube, which becomes suddenly swollen at more or less regular 

 intervals, producing whorls of six clusters of processes, somewhat resembling 

 the rosettes of the sheathiDg tubes of the stem. 



The fruits are produced singly, or two or three together, on one, probably 

 the upper, side of the branchlets, taking rise from pores at the centre (?) of 

 the rosettes. 



The fruit consists of an oogonium with five spiral enveloping cells, as in 

 existing Characeae, but enclosed in a utricle formed or surrounded by a 

 number of elongated adnate processes, somewhat similar to the bract-cells of 

 living species of Charece, converging at the tips and nearly closing in the 

 utricle. Little more than the calcified portion of these bract-like processes 

 adnate to the fruit is preserved (see figs. 1, 2, 4, 6, 7, 8). Up to the present 

 we have not found any trace of the antheridia. 



We have no indication as to the stature of the plant, having found short 

 portions only of the stem, and we have not made out any trace of a rooting 

 system. 



The foregoing description is drawn up from the remains of what is evidently 

 the commonest species, but we have found others which, though different in 

 some respects, belong apparently to the same type. 



In 1891, Saporta, in his ' Plantes Jurassiques,'* described and figured as 

 Chara fruits, under the name of G. Maillardi, some grooved pyriform bodies, 

 which may be the utricles of a species of this genus. 



The production of the "rosettes" is apparently a character shared by 

 at least one of the other genera. The constant number of the branchlets 

 (six) is probably common to all the Characere of these Purbeck beds, as 

 well as the fixed number (twelve) of the sheathing tubes of the stem, when 

 present. 



Among the other genera is one evidently belonging to the Mtellese, having 

 forked branchlets. This is apparently the first satisfactory instance of a 



* ' Paleontolog. Frang.,' ser. 2, Veget.- IV, p. 498, tab. 298 lis, figs. 6 and 7 (1891). 



