PALAEOSTACHYA 67 



vascular supply indicates that the sporangiophores may 

 be regarded as the ventral appendages of the bracts 

 subtending them. > On account of the anomalous course 

 of the sporangiophore bundles, Mr. Hickling regards 

 Palaeostachya as derived from the Calamostachys type. 



4. Cingularia. — We now come to the third type of 

 the Calamarian fructifications which I shortly described 

 above, namely that of Cingularia. Our knowledge of 

 Cingularia, which is chiefly due to the researches of 

 the German palaeobotanist Weiss, 1 is less satisfactory 

 than in the cases already considered. So far we have 

 been dealing with fructifications with their internal 

 structure preserved. Cingularia is not one of these ; 

 it is only known from carbonaceous impressions, and not 

 from petrified specimens, and hence only its external 

 characters are open to investigation. Under these 

 circumstances we cannot feel the same certainty in 

 the interpretation of the facts as in specimens with the 

 whole structure preserved. We may, however, accept 

 Weiss's description as being probably the correct one. 

 The plant itself had the usual Calamarian habit, with 

 a jointed stem and whorled leaves. It appears that 

 the successive whorls were superposed, not alternating 

 as in most Calamarieae. The fructifications were long, 

 very lax cones, with the whorled appendages rather 

 remote from each other (see Fig. 28). 



The conclusion at which Weiss arrived is that each 

 whorl was a double one, and that it consisted of a verticil 

 of coherent bracts running out into sharp teeth at the 

 edges, and of another coherent verticil immediately 



1 Stcinkohlen-Calamarien, i. p. 99, Plates vi.-ix. 1876. 



