326 



CALAMARIEAE. 



these must be added Cingularia, Weiss, a fructification of anomalous struc- 

 ture. Stur 1 considers that he finds his three distinct whorl-traces in regular 

 and characteristic position in each case in the fructification as well as in the 

 stems and branches ; but his speculations on this point have been already 

 noticed, and it is unnecessary to go further into them in this place. It is 

 plain that the impressions, the only specimens here in question, are not to 

 be directly compared with the interior casts, on the study of which this 

 author has founded his views. 



In Calamostachys, Weiss (Fig. 45 A), the umbellate sporangial leaves 

 are inserted exactly in the middle between every two leaf-whorls ; their 

 stalks are at right angles to the axis of the spike, and bear the sporangia 

 at their more or less distinctly expanded and scutiform extremity. Our 

 knowledge of the structure of the fructification in this genus is chiefly 

 derived from a specimen preserved in siderite from Hattingen on the 



Ruhr, which was first described and figured 

 by Ludwig 2 , then named Volkmannia Lud- 

 wigii, Carr. by Carruthers 3 and Calamos- 

 tachys typica, Schpr. by Schimper 4 , and has 

 finally been fully elucidated by Weiss 5 

 with the addition of fine figures. The 

 specimen contains a number of spikes lying 

 parallel to one another, and may therefore 

 be a fragment of a tuft of fructifications. 

 The leaves in the sterile whorl, about twelve 

 in number, are free almost to the point of 

 attachment, and from their horizontal basal 

 portion the lanceolate upper part curves 

 upwards at a right angle, and exactly covers the curved portion of the 

 leaves of the whorl next above. The whorl of sporangiophores inserted 

 between two leaf-whorls has six members ; the members in the suc- 

 cessive sporangial whorls are superposed ; of the twelve members in 

 the leaf-whorls six appear to alternate, six to be superposed. The 

 substance of the sporangiophores, especially in the small scutiform ex- 

 pansion, is partly preserved in a few cases only. But the sporangia 

 themselves, which are suspended in fours in a diagonal position from the 

 scutellum of the sporangiophore, are comparatively well preserved. Their 

 wall, which is of one cell-layer only, at least in its present state, is formed 

 of reticulated cells. The doubts expressed by Weiss 6 respecting the con- 

 nection between the thickening-ridges and the membrane may have no 

 foundation. The sporangia are filled in uniform manner with the globular 



A B 



FIG. 45. Calamostachys. A diagrammatic 

 representation of the strui ture of the spikes in 

 Calamostachys. ft small fragment of the 

 fructification of Calamostachys (Stachannu- 

 laria) tuberculata. Between two sterile whorls 

 is a fertile whorl showing the peculiar prickle- 

 like sporangiophore described in the text. A 

 after Weiss (.i) ; IS after Weiss (6). 



1 Stur (5). Ludwig (1). 



5 Weiss (5), p. 249; tt. 18 and 22-24. 



3 Carruthers (15). 

 4 Weiss (5), p. 253. 



* Schimper (1), vol. i, p. 328. 



