XIV] SELAGINELLITES 87 



The drawing reproduced in fig. 138 is a copy of that of the type- 

 specimen : another specimen, named by Goldenberg, is figured 

 by Halle in his recently published paper. The leaves appear 

 to be distichous : no smaller leaves have been detected, though 

 Halle is inclined to regard the plant as heterophyllous. The 

 sporophylls, borne in slender terminal strobili, are smaller than 

 the foliage leaves and spirally disposed (fig. 138; smaller 

 specimen). Halle succeeded in demonstrating that some of 

 the sporangia contained a single tetrad of spores, each spore 

 having a diameter of 0*4 — 0'5 mm. No microspores were found, 

 but it is clear that the species was heterosporous and that it 

 agrees with recent species in having only four spores in the 

 megasporangium. 



Selaginellites elongatus (Gold.). Fig. 135, B, D. 



1855 Lycopodites elongatus, Goldenberg'. 

 1870 Lycopodium elongatum, Schimper^. 



The shoots of this species resemble the recent Lycopodium 

 complanatum; they differ from those oi Selaginellites primaevus 

 in their long and narrow branches which bear two forms of leaf. 

 The longer leaves, arranged in opposite pairs, are slightly falcate; 

 the smaller leaves are appressed to the axis and have a triangular 

 cordate lamina. Another peculiarity of this species is the 

 occurrence of sporangia in the axil of the foliage leaves, a feature 

 characteristic of the recent Lycopodium Selago. In recent 

 species of Selaginella the sporophylls are always in strobili. No 

 microspores have been found nor the walls of megasporangia, 

 but tetrads of megaspores were isolated by Halle: the spores have 

 three radiating ridges (fig. 135, B) connected by an equatorial 

 ridge. Halle estimates the number of spores (0*45 mm. in 

 diameter) in a sporangium at 20 to 30. In size as in number 

 the spores exceed those of recent species and agree more nearly 

 with the megaspores of S. Suissei. 



It would seem to be a general rule that the spores (mega- 

 spores) of the fossil herbaceous species exceeded considerably in 



1 Goldenberg (55) PL i. fig. 2. = Schimper (70) A. p. 10. 



