1879.] 



of the Fossil Plants of the Coal Measures. 



447 



belong. It unexpectedly proves to be a very small one, being little 

 more than an inch in length. Further specimens have shown that 

 the abnormal peduncles of the macrospores shown in Plate 23, fig. 64, 

 are wholly due to the partial collapse of the spore-wall. Further 

 specimens have also been obtained of the Strobilus and its spores 

 represented in Plate 22, figs. 38-57. These examples possess the 

 central vascular axis in a perfect state, which portion was lackiug 

 in the previously known examples. It proves to have an individuality 

 as distinctive as that of the spores and sporangia which it bore. 



The important discovery by Mr. D'Arcy Thompson, of Edinburgh, 

 of young branches of TJlodenclron with reproductive cones actually 

 attached to the scars characteristic of the genus, finally settles the 

 nature and functions of these scars, showing that they mark the 

 ■positions from which bilaterally arranged deciduous organs of fructifi- 

 cation have fallen. 



The structure of Calamostachys Binneyana has had further light 

 thrown upon it, sustaining my previously expressed convictions that 

 it had a triquetrous axis, and that consequently its affinities were 

 with Asterophyllites and Sphenophyttum, and not with Catamites. A 

 specimen demonstrates that the six vascular bundles going to the six 

 fertile sporangiophores were given off in pairs from the three truncated 

 angles of a triangular vascular axis — an orientation absolutely identi- 

 cal with that represented in similar sections of stems of Sphenopliyllum, 

 published by M. Renault. The recent discovery by Herr Stur, of 

 Vienna, of a plant in which Sphenophylloid and Asterophyllitean 

 leaves are found upon a common stem, establishes the correctness of 

 my previous conclusions as to the very close affinities of these two 

 genera. 



Two new fern petioles or stems have been obtained from Halifax, to 

 which I have given the name of Rackiopteris robusta and lb. insignis. 

 In one specimen of the latter, the large vessels of the central bundle 

 are full of Tylose cells, whilst a second example exhibits no trace of 

 them. This shows the existence or non-existence of Tylose to be a 

 characteristic having no specific value. 



Since my last memoir was written I have obtained several new 

 forms of cryptogamic conceptacles — similar to those previously de- 

 scribed under the generic name of Sporocarpon — as well as been able 

 to throw additional light upon some of those previously described. 

 No clue has yet been obtained as to the plants to which these verv 

 remarkable organisms belonged. 



A large series of specimens from Oldham and Halifax has enabled 

 me to investigate in detail the very curious objects to which Mr. 

 Carruthers gave the name of Traquairia, and which that observer 

 believes to be a form of Radiolarian life. Their very elaborate orga- 

 nization can scarcely be made intelligible without the aid of plates. In a 



