BOOK-NOTES, NEWS, ETC. 375 



" Examples might be quoted in illustration of the risks attending 

 the determination of fossils by external features alone, but it may 

 suffice to mention the case of a specimen originally described as a 

 fragment of a Cretaceous Dinosaur {i.e. a reptile), under the name 

 Aachenosaurus multidens. By the examination of thin sections 

 this supposed bone was shown to be a piece of Dicotyledonous 

 wood." 



As will be seen, the style of the book is straightforward and 

 business-like, but we cannot quite reconcile ourselves to the new- 

 fangled nomenclature which converts the old familiar Scotch Fir 

 into " Scots Pine." 



J. G. 



BOOK-NOTES, NEWS, etc 



At the meeting of the Linnean Society on November 2nd, 1911, 

 Dr. D. H. Scott gave an account of the palaeozoic fern Zygoj^teris 

 Grayi (Williamson). The group of comparatively simple Ferns 

 (Primofilices of Arber, Cmiopteridce, of Seward) to which this plant 

 belongs is chiefly known by petrified specimens showing structure. 

 Correlation with impressions showing the habit has seldom been 

 possible ; fronds, however, belonging to a Zygopteris have been 

 identified. Zygopteris Grayi, a species founded by Williamson in 

 1888, is a rare fossil. A new specimen, from Shore Littleborough, 

 in Lancashire, was found by Mr. Lomax last year, and series of 

 transverse and longitudinal sections were prepared. The general 

 structure of the Shore specimen is that typical of the species ; 

 there is a five-rayed stellate stele, corresponding to a 2/5 phyllo- 

 taxis ; the leaf-trace bundles are given off from the arms of the 

 main stele and each is accompanied by an axillary stele ; scale- 

 leaves or aphlebiae are present on the stem and leaf-base, and 

 adventitious roots are also frequent. The specimen is favourable 

 for showing the characteristic internal xylem, consisting of small 

 tracheides associated with parenchyma, both in the main and the 

 axillary steles. The question whether this species belongs to 

 Ankyropteris or Etapteris, as these genera are defined by Paul 

 Bertrand, has been disputed. The new specimen is certainly an 

 Ankyropteris, as shown by the presence of "peripheral loops " of 

 small-celled xylem on the leaf-trace. Thus the view of Paul 

 Bertrand is confirmed ; it appears to hold good for all known 

 specimens of Z. Grayi. The Shore specimen has a leaf-trace of 

 crescentic form as seen in transverse section ; in this respect it 

 differs from the figured specimens of the species, in which the 

 trace is approximately triangular. A crescentic leaf-trace, how- 

 ever, occurs in one at least of Williamson's type-specimens, so no 

 specific difference can be based on this character. It has been 

 suggested that the organ here called a leaf-trace is ratlier of the 

 nature of the stele of a branch. The Shore specimen, however, 

 shows manifest leaf-trace characters in this organ, while the 

 analogy of other species likewise confirms Stenzel's original inter- 

 pretation ; the branch which is connected with the leaf-trace 

 higher up in its course may therefore retain its traditional name 



