X] ANNULARIA. 339 



about the middle, 1 — 5 cm. in length and 1 — 3 mm. broad, hairy 

 on the upper surface' ; each leaf is traversed by a single vein. 



Fig. 88. Brniioh. of Annularia stellata (Sehloth.). | nat. size. 



Prom a specimen in the Collection of Mr E. Kidston. Upper Coal- 

 Measures, Eadstook. 



Each whorl contains 16 — 32 segments, which are connected 

 basally into a collar or narrow sheath ; the lateral segments are 

 usually longer than the upper and lower. The branches are 

 about 6 — 20 mm. broad, with finely ribbed intemodes 3 — 7 cm. 

 long, bearing verticils of leaves ; the ultimate branches arise in 

 pairs in the axils of the lateral segments of the verticils. 



The strobili are of the Calamostachys' typ6 and are borne 

 on the main branches or possibly on the stem ; they have a long 

 and narrow form and are attached in verticils at the nodes. 

 Each strobilus consists of a central axis bearing alternate whorls 

 of linear lanceolate sterile bracts and sporangiophores, about 

 half as numerous as the sterile bracts ; each sporangiophore 

 bears four ovoid sporangia. 



The anatomical structure of a specimen referred to An- 



nularia stellata has been described by Renault'. The cortex 



1 Potoni6 (93), p. 166. " Vide pp. 351 et seq. 



■' Benault (96), p. 66; (98), PI. xxvm. 



22—2 



