414 



Prof. W. C. Williamson on the [Nov. 15, 



numerous macrospores of a new form. These are round bodies with a 

 curious projecting organ on one side surrounded by a thickened ring of 

 the spore wall, reminding the observer of the projection, with its thickened 

 surrounding ring, seen at the apex of the macrospores of Isoetes lacustris. 

 These macrospores have their exteriors irregularly clothed with numer- 

 ous long radiating hair-like fringes, some of which are simple, others 

 branched twice or three times, whilst in the interior of some of them 

 the endospermic cells are beautifully preserved. Along with these 

 Messrs. Binns and Spencer have discovered a new and very remark- 

 able Lepidostrobus. Its almost spherical sporangia contain numerous 

 spores arranged in tetrasporal clusters, each cluster being imbedded 

 in a larger group of mother and their sister cells, which are exqui- 

 sitely preserved. Each united cluster of four spores is about of 

 an inch in diameter. Whether these objects are a new and very large 

 species of microspore — macrospores clustered in unusual numbers within 

 the same sporangium — or whether they are merely mother cells from 

 which at a later period clusters of microspores would be developed, is 

 doubtful. Some of these tetraspores enclose a number of minute cells. 



Along with the above other smaller forms of what appear to be macro- 

 spores have been found. Their exterior is adorned with short trifid 

 appendages, calling to memory the fossil Xanthidia of flint and the 

 zygospores of some of the Desmidieae. Some remarkable sporiferous (?) 

 cavities imbedded in parencl^ma significantly recall the imbedded 

 sporangia of Opliioglossum vidgatum, whilst a very singular section of a 

 rather large hollow spherical body, composed of a single layer of hour- 

 glass-shaped cells arranged vertically to its surface, and many of which 

 cells are prolonged into external hairs, bears no inconsiderable resemblance 

 to a section of a sporangiocarp of Isoetes lacustris. 



Ferns. — Two types of stem or petiole, not hitherto met with in York- 

 shire or Lancashire, have been found recently. One of these is from 

 Oldham, whence it was obtained by Mr. Isaac Earnshaw. It is a petiole 

 differing so little from the Chorionoyteris Gleichai of Corda that the lecturer 

 has included it in his provisional genus Rachiopteris sls^R. Gleichce. 



The affinities of the second plant are more doubtful. It is a cylindrical 

 axis from Halifax, where it was found by Messrs. Spencer and Binns, to 

 both of whom the lecturer is indebted for specimens of it. Its most con- 

 spicuous feature is its very large central vascular bundle, which is a cy- 

 lindrical mass of barred vessels. The bundle is of much larger dimensions, 

 proportionate to the size of the stem, than in any Fern or Lycopodiaceous 

 plant that has hitherto been found in the Coal-measures. It gives off 

 branches almost at right angles to the main axis, and these are met with 

 of all sizes, from *066 of an inch down to a mere speck. In some respects 

 this plant has a Lycopodiaceous aspect, especially in the size and appear- 

 ance of its central bundle. The bark, too, consists of an inner layer of deli- 

 cate parenchyma and an outer one of coarser cells. These two are Lepido- 



