230 Notices of Memoirs — Bentham — On Fossil Mimosece. 



from the present cliffs. He noticed, also, the westward movement 

 of the shingle from Lul worth towards Weymouth, owing to the 

 interference of the Isle of Portland with the force of the S.S.W. 

 wind-waves, and considered that none of the Devon and West 

 Dorset shingle beach now passed the Bill of Portland, and that other 

 such breaks might exist to the eastward whenever similar conditions 

 were repeated. He explained the origin of the Fleet, like that of the 

 Weymouth backwater, and of the Lodmore marshes, by the growth 

 of the Chesil Bank on the one hand, and of the Bingstead and Wey- 

 mouth Beach on the other, gradually damming in portions of the old 

 coast-line. Those beaches themselves travelled on a line along 

 which the opposing forces of the wind- waves and tidal currents and 

 the inertia of the mass to be moved were balanced. These views 

 were stated to be in conformity with the theoretical opinion expressed 

 on abstract grounds by the Astronomer Eoyal, and with the ex- 

 perience of practical persons residing on the spot. 



II. — Eeview of Professor Schimper's Fossil Mimose^i. 1 



IN the prefatory matter to the present paper I have made no reference 

 to any fossil remains of Mimosece; for at the time of drawing it 

 up I had no ready means of ascertaining what evidence on the subject 

 had been supplied by palgeontologists, and I had not yet heard from 

 Professor Schimper, who had kindly promised to communicate with 

 me on the subject. Since, however, the early sheets of this paper 

 were printed off, the third volume of his magnificent work on Vege- 

 table Paleontology has reached us ; and in it I find that a number of 

 supposed fossil Mimosece from the Central-European Tertiary are 

 described and figured, and referred severally to the genera Prosopis, 

 Inga, Entada, Mimosa, and Acacia. The great majority of the 

 species so determined are founded on impressions of leaves only; 

 and these I pass entirely over ; for although without collateral 

 evidence it is impossible to deny that they may belong to the genera 

 in question, it is equally impossible to affirm that they do so belong ; 

 for none of them show forms or venation exclusively characteristic 

 of any of these genera. I thus see no reason to conclude on this 

 evidence that any Inga. Mimosa, or Phyllodineous Acacia was in 

 part of the Tertiary period an inhabitant of that part of Europe, 

 when other evidence would tend to an opposite conclusion. With 

 regard to Prosopis, the presumption that it might have been there is 

 to my mind neither confirmed nor refuted by the fossil impressions 

 described as Prosopis leaflets. On the other hand, those fruits of 

 which so many excellent impressions are figured by Schimper, point 

 to species of Acacia, Entada, and perhaps Albizzia, very similar to 

 those now found in Africa — a case analogous to that of the Podo- 

 gonium, of which specimens so very perfect have been preserved as 

 to enable us satisfactorily to identify it as closely allied to some 

 African Caasalpineous genera not yet quite extinct. 



Descending to particulars, the fruits figured by Schimper, pi. cvi. 



1 Extracted from a revision of the sub-order Mimosece, by George Bentham, Esq., 

 F.K.S., 1875. Linn. Trans, vol. xxx. pt. 3, pp. 646, 647. 



