338 CALAMITES. [CH. 



leaves in one plane, which is commonly insisted on as a generic 

 character, is an original feature, or how far it is the result 

 of compression in fossilisation. Probably the leaves of a living 

 Annularia were spread out at right angles to the axis, as in 

 the Werticils' of such a plant as Galium. 



Dawson^ has described some fossils from the Devonian rocks 

 of Canada as species of Asterophyllites ; the figures bear a closer 

 resemblance to the genus Annularia. The same author figures 

 some irregularly whorled impressions as Protannularia, which 

 appear to be identical with a fossil described by Nicholson^ from 

 the Skiddaw slates (Ordovician) of Cumberland as Buthotrephis 

 radiata, but the specimens are too imperfect to admit of 

 accurate determination. 



Annularia stellata (Schloth.). Fig. 88, 



1820. Casuarinites stellatus, Schlotheim^. 



1826. Bornia stellata, Sternberg*. 



1828. Annularia longifolia, Brongniart^. 



1834. Asterophyllites equisetiformis, Lindley and Hutton''. 



1868. Asterophyllites longifolius, Binney''. 



1887. Annularia Geinitzi, Stur^. 



1887. Annularia westphalica, Stur. 

 This species was figured by Scheuchzer^ in his Herbarium 

 Diluvianum, and compared by him with a species of Galium 

 (Bedstraw). Brongniart first made use of the generic name 

 Annularia for this common Coal-Measure species, which may 

 be defined as follows: — 



Stem reaching a diameter of about 6 — 8 cm., with internodes 

 6 — 12 cm. in length, the surface either smooth or faintly ribbed. 

 Primary branches given off in opposite pairs from the nodes, the 

 lateral branches giving off smaller branches disposed in the same 

 manner. The smaller branches bear verticils of leaves at each 

 node ; both leaves and ultimate branches being in one plane. 

 The leaves are narrow, lanceolate-spathulate in form, broadest 



1 Dawson (71). 



2 Nicholson (69) PI. xviii. B. Nicholson's specimens are in the Wood- 

 wardian Museum, Cambridge. ^ Schlotheim (20), p. 397. 



4 Sternberg (26), p. xxviii. ^ Brongniart (28), p. 156. 



6 Lindley and Button (31), PI. cxxiv. ^ Binney (68), PI. vi. fig. 3. 



8 Stur (87), PL XVI b, and Pis. ivb and xiii. 



9 Scheuchzer (1723), p. 63, PI. xiii. fig. 3. 



