GNETOPSIS, SCHUTZIA, DICTYOTHALAMUS, CALATHIOPS. 127 



origin have been described as Ephedrites, but they show little of nothing 

 characteristic. The fructifications also from the Jurassic deposits of Siberia, 

 which Heer 1 assigns to his Ephedrites antiquus, are more than doubtful. 

 Schenk's 2 excellent critical remarks on this subject should be consulted. 

 Renault 3 speaks of some of the seeds from the Coal-measures which were 

 noticed in the last chapter in connection with Cordaiteae, namely Sama- 

 ropsis, Cardiocarpus orbiculafis, Brongn., and Stephanospermum, as doubt- 

 ful remains of Gnetaceae. In his explanation of the plate in Brongniart 4 

 he gives the following reason for his opinion as regards that form : ' This 

 seed is surrounded by two envelopes which appear to be independent of one 

 another and not intimately connected together like the endotesta and sarco- 

 testa in other seeds of the group of Cardiocarpeae ; it reminds us in this 

 respect of Certain seeds of Gnataceae, of Gneturri Thoa, for example, and 

 Gnetum urens. Since then there is a piece of the inner integument 

 evidently remaining, we should in fact have three envelopes before us, as in 

 Gnetum ; but it is confessedly very hazardous to conclude the number and 

 character of the integuments from the structure of the envelopes of Jthe 

 seed, especially where, as in this case, the division between sarcotesta and 

 endotesta may very easily have been a consequence of maceration of 

 the seed. 



Lastly, the same author 5 describes as Gnetopsis elliptica certain fructi- 

 fications which he has discovered in the pebbles from the Upper Coal- 

 measures of Grand' Croix. In Saporta and Marion 6 , where these fossils 

 are figured for the first time from Renault's drawings, the genus is. placed 

 next to Ephedra. Then two more species were added to the genus, 

 Gnetopsis trigona and G. hexagona, Ren. and Zeill., forms found only as 

 impressions in the carboniferous mountain-district of Commentry. The 

 remains of the flower of Gnetopsis elliptica are of complicated structure. 

 The transverse section (Figi n, D] shows two distinct opposite bract-like 

 leaf-forms with curved surfaces, which are traversed by numerous parallel 

 vascular bundles of normal structure and normal arrangement, and are covered 

 on the inner side With long close-set hairs which fill the hollow of the leaf. 

 These leaves divide above, as we learn from successive transverse sections, into 

 an uneven number of apices, each of which is supposed by Renault to have 

 a vascular bundle corresponding to it. Between the hairs which fill the inner 

 space are seen the transverse sections of several ovules, the normal number 

 being four, so that there are two to the space enclosed by each of the two 

 enveloping leaves. Since the two pairs of ovules are not inserted at the same 

 level on the Bummmit of the axis, they are seen at different heights on the 

 transverse section. Further irregularities often occur, the number of de- 



1 Heer (5), vol. 411, t. 14. 2 Zittel (1), p. 354- s Renault (2), vol. iv. 4 Brongniart 



(6), t. 7. 5 Renault (2), vol. iv, tt. 20, 21, 22. Saporta et Marion (2), p. 1 8 1. 



