XXIl] SCOLECOPTERIS 401 



sporangia are free and united only by the proximal end to 

 a central receptacle (fig. 291, F, G). He describes the indi- 

 vidual sporangia as possessing a rudimentary annulus, a 

 comparatively strong wall, and terminating in a pointed distal 

 end. He emphasises the greater degree of cohesion between 

 the sporangia of Asterotheca as the distinguishing feature of 

 that genus ; but this is a character difficult to recognise in some 

 cases, and from the analogy of recent ferns one is disposed to 

 attach little importance to the greater or less extent to which 

 sporangia are united, at least in such cases as Asterotheca and 

 Hawlea when the cohesion is never complete. 



Scolecopteris. 



Zenker^ gave this name to detached fertile pinnules from 

 the Lower Permian of Saxony, which he described as Scole- 

 copteris elegans. He recognised the fern nature of the sori 

 and suggested that the pinnules might belong to the fronds 

 of one of the " Staarsteinen " (Psaronius), a view which subse- 

 quent investigations render far fi:om improbable. The sori, 

 which occur in two rows on the lower surface of the small 

 pecopteroid segments with strongly revolute margins (fig. 291, 

 H — K), contain 4 — 5 sporangia attached to a stalked receptacle 

 comparable with that of Marattia Kaulfussii. These pedicellate 

 synangia were fully described by Strasburger^, who decided in 

 favour of a Marattiaceous alliance. The lower portions of the 

 distally tapered sporangia are concrescent, the distal ends being 

 free (fig. 291, H). Stur includes in Scolecopteris the common 

 species Pecopteris arborescens (fig. 376), but Kidston* states 

 that the British example of Scolecopteris is S. polymorpha. 

 Brongn. from the Upper Coal-Measures. 



Scolecopteris elegans Zenk. furnishes an example of a plant, 

 or plant fragment, which has been assigned to the animal 

 kingdom. Geinitz* described silicified pinnules as Palaeojulus 

 dyadicus, the generic name being chosen because of the re- 



1 Zenker (37). ^ Strasburger (74). ^ Kidston (91^) p. 20. 



* Geinitz (72). See Solms-Laubach (83), who gives in full the early history 

 of the genus Scolecopteris. 



