142 Morphology BOOK i 



1885 with the fossil known as Astromyelon. He confirmed 

 and extended his observations in a further memoir in 

 1896. Williamson and Scott also published a very com- 

 plete account of their anatomy in 1894. 



The fructifications which existed in the group were 

 studied by several observers. The first type known, 

 CalamostacJiys, was first shown to belong to a Calamite by 

 Carruthers in 1867. Heterospory was demonstrated in one 

 of these cones, C. Casheana, by Williamson, in 1880. 

 Another genus, Annularia, which was studied by Grand'- 

 Eury and Renault, bore cones of the same type, in which 

 heterospory was recognized by Renault, in 1873. The 

 fructification was known at that time as Bruckmannia. 



The second type was studied by Williamson in 1869, 

 and was called by him Palaeostachya. He considered it to 

 be the true representative form of Calamite fructification. 

 He investigated it more fully in 1887. J . E. Weiss described 

 a third type, Cingularia, in 1876, but it was associated only 

 with casts and not with petrified specimens. The fourth 

 type, Archaeo catamites, which most nearly approaches 

 recent Equisetaceae, was figured by Stur in 1875, but his 

 material was imperfect, as he only had badly preserved 

 cones for examination. Kidston studied this form in 1883; 

 and at the same time showed that Pothocites, which had been 

 held to be the inflorescences of Monocotyledonous plants, 

 really belonged to the group. Renault also described some 

 fragmentary fructifications belonging to the Calamites in 

 1896. 



Two classifications of the Calamarieae have been made. 

 The first was that of J . E. Weiss in 1884 ; it was based mainly 

 on the form of the stem and its medullary casts. A second 

 and more satisfactory one was that of Grand'Eury, to whom 

 we owe so much of our knowledge of the group as far as 

 its vegetative habit is concerned. It was published in 1890. 

 It made three main divisions of the Calamites, Annularia, 



