186 



logical scale as the Devonian, and by the Carboniferous they are 

 very numerous in some localities, the coal-measures of both hemi- 

 spheres furnishing them in considerable variety. 



Little beyond descriptions based on external form are known 

 of the seeds from American localities, where their preservation is 

 poor as compared with the beautifully silicified and calcified re- 

 mains from some of the European localities. 



Brongniart as recently as 1881 * may be said to have laid the 

 foundation for their scientific study. 



In the light of the recent work, principally of Professors 

 Oliver and Scott, the further study of these and similar remains 

 assumes a special importance, and my excuse for this notice is 

 the arrival in this country of the completed memoir of the above 

 authors on the seed Lagenostoma Loinaxi,\ which is thus far the 

 most interesting as well as the best known fossil seed. 



The fact of its definite reference to the plant which bore it is no 

 little credit to the sagacity of the authors and to the methods of 

 study inaugurated by the late Professor Williamson. The pres- 

 ent memoir, which is well illustrated by seven plates and two text 

 figures, sets forth in detail the structure of the seed and its 

 cupule. The authors have handled all the extant material 

 known, and their conclusions are admirable and convincing. 

 They propose for this and similar fern-like spermatophytes a new 

 class, the Pteridospermeae, for which Ward % would establish the 

 sub-kingdom Pteridospermaphyta in the anticipation, already 

 partially verified, that the three great phyla of Paleozoic cryp- 

 togams independently acquired the seed habit. 



The preHminary contribution of Oliver and Scott was read be- 

 fore the Royal Society in May, 1903, and in the short interval 

 since we are able to record numerous contributions along the 

 same lines. Since Potonie in i 897 established the order Cycad- 

 ofilicales it has seemed probable that numerous forms o{ Alctliofy- 

 fcj-is, Pccoptcris, Odontoptcris, Ncuroptcris, Splictioptcris, etc., were 



* Brongniart, Adolphe. Keclierclies sur les graines fossiles silicifi^es. 



t Oliver, F. W., and ScoU, I). \\. On the Structure of tlic Palaeozoic Seed 

 Lagenostoma Lomaxi. I'liil. Trans. Koy. .Soc. I.ond. ]>. 197 : i()3-247. //. ^-ip. 

 17 Au 1904. 



X Ward, L. F. Science, II. 20: 25, 279. 1904. 



