]; EQUISETACEAE, MAKSfLEOIDEAE, 



In the formations which succeed the Keuper much smaller species take 

 the place of Equisetites arenaceus ; E. Miinsteri, for example, which has been 

 fully discussed by Schenk a , is characteristic of the Rhaetic deposits. This 

 species is distinguished by its broad flat furrows and its sharp ribs, of which 

 there are a few only in the circumference of the stem. A globular fructifi- 

 cation has been found attached to the organs of vegetation. In E. colum- 

 naris 2 from the Lower Oolite of Scarborough and Whitby we have another 

 colossal form resembling E. arenaceus. Several smaller species from the 

 same formation in the Southern Alps have been examined by Zigno 3 ; of 

 E. Burchardti from the Walderkohle we have already spoken. It is 

 unnecessary to go further into the consideration of the many forms 

 described from the more recent formation. 



Having thus proceeded upwards in our survey from the Equisetites 

 arenaceus of the Keuper, we must add a few words respecting the pre-Tri- 

 assic Equisetaceae. There are first the remains from the Coal-measures 

 which Schimper 4 has brought together under the name Equisetides. As 

 these are only short bits of stem with single sheaths and nothing is known 

 of the fructifications, they must be classed among the most doubtful of 

 fossils. Equisetides lingulatus 5 from the Coal-measures of Wettin and E. 

 brevidens 6 may be mentioned as the best-known examples. The more 

 thorough examination of these species must be preceded by the procuring 

 of material from the coal-districts, for there are but few specimens in the 

 collections. They do not appear to be at all abundant, but they are 

 inconspicuous and may have been overlooked. The reader should refer 

 to the remarks which will be found on a later page in connection with 

 Cingularia and Calamostachys. Dawson 7 has figured as Equisetides 

 Wrightiana a very unlikely looking fossil from the Upper Devonian beds of 

 Chemung ; this according to Hall 8 is the remains of a Crustacean, and 

 represents two abdominal segments of a creature not unlike the genus 

 Stylonurus. 



Here must be mentioned the fossil known as Equisetum mirabile 9 , a 

 peculiar form, in which there is much that still remains to be determined ; 

 a full discussion of it accompanied by fine and careful figures will be found 

 in Weiss 10 and Stur n . The latter author has founded a new genus for this 

 plant, and named it Eleutherophyllum. Equisetum mirabile is one of the 

 very rarest of the fossils of the Coal-measures, and has hitherto been known 

 only in a few fragments of impressions from the Waldenburg district. Stur 

 has given the names of the Museums in which these specimens are preserved. 



1 Schenk (3). a Brongniart (1), vol. i, t. 13. 3 de Zigno (1), vol. i. * Schimper (1), 



vol. i, p. 286. s Geraiar (1), t. 10, f. 3 ; Weiss (5), t. 16, f. 10. 6 Schimper (1), t. 17, f. 4. 



7 Dawson (4). " Wright (1), Explanation tot. 15, f. i. 9 Sternberg, Graf von (1), Heft 5-8, 

 t. l,f. i a and b. I0 Weiss (6), p. 133 ; t. 18, f. 2, and (5), p. 149; t. l6a, f. 9. " Stur (5), 



p. 171 ; t. i, ff. i-;. 



