402 FILICALES [CH. 



semblance to Millipedes such as the genus Julus. The mistake 

 is not surprising to anyone who has seen a block of siliceous 

 rock from Chemnitz crowded with the small pinnules with 

 their concave surfaces formed by the infolding of the edges. 

 Sterzel', who pointed out the confusion between Myriapods 

 and Filices, has published figures which illustrate the deceptive 

 resemblance of the pinnules, with their curved lamina divided 

 by lateral veins into segments, to the body of a Millipede (fig. 

 291, K). He points out that Geinitz searched in vain for the 

 head and legs of Palaeojulus and expressed the hope that 

 further examination would lead to fresh discoveries : the exami- 

 nation of sections revealed the presence of sporangia and 

 demonstrated the identity of Palaeojulus and Scolecopteris. 



Discopteris. 



Stur^ instituted this genus for fertile fronds from the Upper 

 Carboniferous Schatzlarer beds, including two species Discopteris 

 karwinensis and D. Schumanni. He described the small 

 Sphenopteroid pinnules as characterised by disc-shaped sori 

 made up of 70 — 100 sporangia attached to a hemispherical 

 receptacle : the absence of a true annulus led him to refer the 

 genus to the Marattiaceae. In his memoir on the coal-basin of 

 Heraclea (Asia Minor), Zeiller' instituted the species Sphenopteris 

 (Discopteris) Rallii and figured sporangia resembling those 

 described by Stur in the possession of a rudimentary " apical 

 annulus." He compared the sporangia with those of recent 

 Osmundaceae and Marattiaceae. In the later memoir on the 

 Upper Carboniferous and Permian plants of Blanzy and Creusot, 

 Zeiller* gives a very full and careful description of fertile 

 specimens of Sphenopteris {Discopteris) cristata, a fern origin- 

 ally described by Brongniart as Pecopteris cristata^ ^ Many of 

 the Sphenopteroid pinnules of this quadripinnate fern frond 

 show the form and structure of the sori with remarkable 

 clearness in the admirable photographs reproduced in Plates 

 I. — III. of Zeiller's Blanzy memoir. The lobed pinnules of this 



1 Sterzel (78) ; (80). 2 Stur (85) p. 140. ^ Zeiller (99) p. 17. 



* Zeiller (06) p. 10. ^ BroDgniart (28) A. PI. cxxv. fig. 4. 



