182 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Other genera, especially Protopitys and Medullosa, 

 were briefly referred to, as also showing a combination of 

 Fern-like with Cycadean characters, and indicating that 

 there were probably several distinct lines of descent, 

 starting from various groups of the Ferns, and leading in 

 the direction of Cycad-like plants. The evidence, though 

 at present almost limited to vegetative characters, was 

 regarded as sufficient to establish the existence of an 

 extensive intermediate group in the borderland between 

 Ferns and Cycadeae, taking the latter term in a wide 

 sense. The lecturer, however, pointed out that these 

 intermediate forms must not be regarded as belonging to 

 the direct line of descent of our living Cycads ; the 

 genealogical tree of the Vegetable Kingdom (like that of 

 animals) was far more complex than we easily realized, 

 and the chances were much against our lighting on 

 " missing links," i.e., the direct ancestors of living plants. 



It now seemed certain that a number of the well- 

 known Fern-like fronds of the Coal-measures, including 

 species of the so-called genera Sphenopteris, Alethopteris, 

 and Neuropteris, really belonged to these transitional 

 forms, though many others were known to be true Ferns. 



Passing on to the evidence from the Secondary rocks, 

 the lecturer dwelt on the abundance and beauty of the 

 Cycadean remains representing both leaves and stems 

 from the Oolite, Wealden and Lower Greensand. He 

 pointed out, however, that only in the rarest cases was 

 there any evidence for the fructification having been of a 

 truly Cycadean type. The best known specimens of 

 reproductive organs in these plants were of quite peculiar 

 structure, totally unlike the cones of any existing Cycads. 

 The classical genus Bennettites, which might be called the 

 ArchcBopteryx of the Vegetable Kingdom, was described 

 at length. These remarkable plants, now so well known 



