252 REPORT ON THE STATE CABINET. 



III. 



Polypary with a double aud single series of cells; the stipes simple below 

 with a series of cells on each margiu, and becoming dichotomous above 

 with a single series of cells on the outer margin. Other forms having the 

 polypary divided from the initial point with a single series of cells on each 

 division. Dickanograptus,* Hall. 



IV. 



Polypary with four series of cells, the laminae united rectangularly by their 

 axes, giving a cruciform arrangement to the parts. Phyllograptus, Hall. 



V. 



Species having a common trunk or stem, or growing in sessile groups of stipes 

 from a common origin, without distinct bilateral arrangement of the parts. 

 Cellules in single series on one side of the stipes or branches, and arranged 

 alous a common canal or axis. 



1. Branches free, developed in a dichotomizing manner from a 

 common trunk. Cellules in contact or closely arranged. 



Dendeograptus, Hall. 



2. Branches unfrequently and irregularly connected by transverse 

 processes. Callograptus, Hall. 



3. Stipes and branches more or less regularly united in a reticulate 



frond. DiCTYONEMA, Hall. 



4. Stipes round or flattened, growing in groups, and bifurcating 



above; margins denticulate; surface rough or scaly. [77ze 

 relatione of this genus are not fully determmed.j Inocadlis, Hall. 



VI. 



Species having a common axis or rachis, with slender lateral alternating 

 branchlets. Cellules unknown. Thamnograpxus, Hall. 



VII. 



Species having a common axis, more or less frequently bifurcating, with 

 pinnulffi closely and alternately arranged on the opposite sides; cell-apertures 

 on one face of the piunulse. - Ptilogeaptus, Hall. 



VIII. 



A simple flexuous rachis, with slender flexuous flattened jjinnulae, arranged in 

 alternating order, at close and regular intervals, on the two sides. Cell-aper- 

 tures unknown or circular?. Buthograptus, Hall. 



IX. 



Strono- stems, which are numerously branched. Branches and branchlets 

 slender, arranged in whorls. Cellules undetermined. Oldhamia? Forbes. 



* See supplementary notes. 



