ZOOLOaY AND BOTANY^ MICROSCOPY, ETC. 417 



B. CBYPTOGAMIA. 



Cryptogamia Vaseularia. 



Stigmariae.* — Professor Harker has made the following determina- 

 tion of the species of Stigmaria found by B. Wethered in the Durham 

 coal-beds. The microspores strikingly resemble those of Isoetes, 

 especially when gently crushed. The triradiate markings of the 

 fossil spores were almost exactly like the flattened three radiating 

 lines which mark the upper hemisphere of the microspores of Isoetes 

 lacustris. He suggests for the carboniferous plant the generic title 

 Isoetoides. 



In the discussion which followed the reading of this paper, Mr. 

 W. Carruthers and Mr. W. Boyd Dawkins did not agree with the 

 author in identifying these spores necessarily with the form allied to 

 Isoetes. Neither true woody tissue nor sporangia are to be found in 

 coal, although macrospores and microspores abound. Coal is composed 

 of two principal elements, carbon proper and a fossil resin ; the 

 blazing property of coal is due to the latter, which is composed 

 mainly, but not entirely, of fossil spores. 



Muscineae. 



Cephalozia.l — In addition to the characters hitherto employed 

 for distinguishing the families and genera of Hepaticse, E. Spruce 

 considers the following as of value : — (1) The origin of the branches, 

 which are either all ventral, as in Cephalozia, Calypogeia, &c., or all 

 lateral, as in Lejeunia, Badula, &c. (in Frullania and Scapania all 

 are exactly axillary ; in Lejeunia and Badula infra-axillary, nearer 

 the outer base of the leaf). (2) The origin of the angles of the 

 perianth, which originate either from the marginal coalescence of 

 nearly flat leaves, as in Lophocolea, Plagiocliila, &c., or from the 

 wedge-shaped leaves, as in Cephalozia, Scapania, &c. (3) The structure 

 of the wall of the capsule. (4) The number of sexual organs, 

 especially of the male, which is very constant in many genera. 



Then follows an exhaustive diagnosis of the genus Ceplmlozia, of 

 its subgenera, and of most of its species. The most important generic 

 characters are : — Prothallium filiform ; branches of ventral origin ; 

 leaves flat or curved inwards, never reflexed ; perigonial leaves always 

 with only a single male organ ; female inflorescence capitular, lateral, 

 with its leaves in three rows ; perianth free, triangular-wedge-shaped, 

 the third edge always ventral ; cap free ; wall of capsule with 

 semicircular fibres ; elaters bi-spiral. 



The genus is divided into eight subgenera, and a large number of 

 species are described. The first two subgenera, each comprising 

 only a single species, are thallose, the rest foliose. Several genera 

 nearly allied to Cephalozia are also described, making up the author's 

 tribe Trigonanthege. 



* Abstr. Proc. Geol. Soc. London, March 5, 1884. 



t Spruce, R., ' On Cephalozia, a genus of Hepaticsa.' Malton, 1882. Seo 

 Bot. Centralbl., xv. (1883) p. 300. 



Ser. 2.— Vol. IV. 2 F 



