524 Report of the State Geologist. 



GrLAUOONOME, GoldfuSS. 



(Petrefacta Germanica, Yol. I, p. IGi), 1826;. emended by Lons- 

 dale in Murchison's Silurian System, p. 677, 1839.) 

 Type, Glauconome disticha, Goldfuss. 



(Plate 8, figs. 8-15.) 

 Zoarium consisting of a main stem or rachis, from which pro- 

 ceed simple lateral branches, at regular intervals, and occasionally 

 branches having the same manner of growth as the primary 

 rachis ; celluliferous on one face ; cell apertures disposed in two 

 longitudinal, parallel rows ; usually separated by a carina. 



ICHTHYO RACHIS, McCoy. 



(Garb. Foss. of Ireland, p. 205. 1844.) 

 Type, Ichthyoraehis Newenhami^ McCoy. 



- (Plate 8, figs. 16-31.) 



Zoarium plumose, consisting of a rachis with short lateral 



branches or pinnules; celluliferous on one face. Gn the rachis the 



cell apertures are disposed in five or more rows, laterally in 



oblique ascending order ; usually three ranges on the branches. 



Family Thamniscidae, King, emend. 

 The following genera are included in this family : 

 Thamnisous, Thamnocella, Cbisinella and Diplopora. 



Thamnisccis, King. 



(Ann. and Mag. N^at. Hist., 2d Series, Yol. Ill, p. 309. 1849.) 

 Type, ThamnisGus dubius, King. 



(Plate 9, figs. 14-18.) 



Zoarium fruticose, giving forth lateral branches or bifurcating, 

 on one plane ; branches numerous, frequently of clavate appear- 

 ance ; not connected by dissepiments ; celluliferous on one face ; 

 cell apertures in quincunx order or irregularly disposed. 



King's diagnosis. " The typical Thamniscidia ; stems frequently 

 and irregularly bifurcating, more or less on one plane ; cellu- 

 liferous on the side overlooking the imaginary axis of the coral . 

 cellules imbricated and arranged in quincunx; gemmuliferous 

 vesicles overlying the cell apertures." 



