Maryland Geological Survey 221 



Most of the supposed species of Baieropsis are referred in the present 

 work to AcrostichopteriSj with which they are obviously allied in in- 

 stances where they are not actually identical. They present no characters 

 which are clearly those of the order Ginkgoales, except their subdivided 

 fronds, which are suggestive of Baiera or Jeanpaulia, but might equally 

 suggest various living Polypodiacege, e. g., Actinopteris and Rhipidopteris, 

 or the family Schizgeacese. Among fossil species they are very similar 

 to forms referred to Splienopteris, Palmatopteris, etc. Considerations 

 which point away from Baiera in the direction of the ferns are the fine 

 inequilateral outline of the leaves (pinnules), their decurrence, and their 

 arrangement in a pinnate manner in a single plane. As has already been 

 shown the species Baieropsis macropJiylla Fontaine and part of Baieropsis 

 expansa Fontaine have furnished fructifications which ally them ^\dth 

 the family Schizgeacese. 



With regard to the botanical position of Acrostichopteris little is 

 known. According to Fontaine : " The genus in the naked sori is like 

 Poly podium, but in most features stands nearest to Acrostichum, much 

 resembling the section Rhipidopteris. In this latter, however, the fructi- 

 fication is borne on separate pinnules. If we place the fructified pinnules 

 of Rhipidopteris as basal segments on the sterile ones, we have a form 

 strikingly like Acrostichopteris. This genus has also some resemblance 

 to Marsilea." 



Seward,* on the strength of ^Fontaine's conclusions, as quoted above, 

 places the genus in the Polypodiacea3. Potonie ^ places it as a synonym 

 of his Palmatopteris in the artificial group of Sphenopterides. 



There is considerable collateral evidence for the reference of these 

 forms to the family Schizseacese, or to what answered to this family in a 

 general way in Mesozoic times. This evidence consists of a relationship 

 of this sort shown by fertile specimens of Baieropsis expansa Fontaine 

 and Baieropsis macrophylla Fontaine, which the writer has united ^ to 



1 Seward, Wealden Fl., pt. i, 1894, p. 60. 



^ Potonie in Engler and Prantl, 1902, p. 490. 



^ Berry, Annals of Botany, vol. xxv, 1911, pp. 193-198. 



