EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 11 



are preserved in any one specimen. One specimen gives the impression 

 that there were only four sporangiophores and six bracts per whorl. In 

 another specimen there are four sporangiophores and probably 12 bracts. 

 It is not certain whether the sporangia were attached to a plate or to 

 small extensions of the sporangiophore. In one specimen there seems to 

 be a plate, whereas in a second specimen the plate cannot be observed. 

 The cone has at its tip a little tuft apparently of four bracts. The 

 sporangia were oval and are now flattened. 



Discussion . — The Calamostachys species described belongs to the 

 Mesocalamltes found in the same flora. There are three specimens that 

 show cones attached to the axis. Leggewie and Schonefeld (l96l) found 

 Calamostachys sengsensis associated with Mesocalamites cistiiformis . 

 Nine other species of Calamostachys that supposedly belong to Mesocal- 

 amites are known from the Namurian. Our specimens are similar in size 

 and characteristics to C. andanensis. All other species of similar 

 size can be excluded owing to differences in the shape of the bracts. 

 In general appearance the Spencer Farm material resembles C. binneyana, 

 which is known from petrifactions throughout the Upper Carboniferous. 

 However, C. binneyana has six sporangiophores per whorl and the bracts 

 are shorter than in our form. Purkynova (1970) reported C. ramosa from 

 the Namurian A of Czechoslovakia. Her figures and description fit our 

 specimen very well. However, Calamostachys ramosa was used for the 

 fructifications of Calamites carinatus (= Calamltes ramosus) , which oc- 

 curs in the Westphalian A to C (Boureau, 196^+, p. 273), and is quite 

 different from the Mesocalamites in the Spencer Farm Flora. 



Remy and Remy ( 197 5b) demonstrated that material described as 

 Calamostachys represents two different organizational plans, in which 

 the vascularization of the sporangiophore differs. Our material does 

 not show the vascular bundle; therefore, we must retain the genus Cal- 

 amostachys sensu amplo. 



FERNS 



Alloiopteris gracillima (Newberry) D. White 



Text fig. 5A-C; pi. 2, figs. 1-1* 



Synonymy 



1873 Odontopteris gracillima Newberry, p. 382-383, pi. 

 k6 9 figs. l-3a. 



1908 Alloiopteris gracillima D. White, p. 269 



Description . — Pinnules k to 5 mm long, 2 mm wide, inclined U5 

 toward the tip of the pinna; pinnule rhomb oidal-shaped, smaller pinnules 

 fused with neighboring pinnules; one vein enters each pinnule, and forks 

 twice; older pinnules splitting up into three lobes; some pinnules have 

 three teeth at the tip. Basal catadromic and anadromic pinnules are 

 aphleboid and lacerated; contain about 6 to 10 teeth. Pinna long, strap- 

 shaped, inserted at an angle of 35° to 70°; pinna more than 60 mm long 

 and 3 to 5 mm wide; pinna of lower order more than 200 mm long and more 

 than 100 mm wide; more than 26 pinnules on one side of a pinna. 



