354 PROCEEDINGS OF THE 



strata of Western Scotland, leaving at that time two other forms 

 for further determination. One of these was a stout form of 

 Glaiiconome, closely allied to the species which we have named 

 G. retroflexa, but differing from it in the number of cell pores 

 between a given number of branchlets, and in one or two other 

 points of external structure. The other form, from the frag- 

 ments then found, we also believed to be a species of Glcmconome, 

 allied by its double cell pores to our sub genus Diplopora. Of 

 both species better preserved specimens have since turned up, 

 and of the latter a small frond has been found which shows that 

 it was fenestrated in its upper portion, and agreeing in general 

 characters with the Carboniferous forms of Stjnodadia, in which 

 genus we now provisionally leave it; not being, however, quite 

 satisfied that the characters of the Carboniferous and Permian 

 Synodadia are exactly the same. 



Glauconome robusta, n. sp. 



Polyzoary erect, slightly flexuous, bipinnately branching at 

 irregular intervals. Branchlets opposite, or slightly sub -alternate, 

 bent towards obverse face, seven in one quarter inch. Cells oval, 

 alternate, about their own length apart, sixteen in one quarter 

 inch, bounded on main branches and branchlets by a prominent, 

 rounded, tuberculated keel, which gives to the cells a buried 

 appearance. Tubercules on keel large, irregularly placed, seven 

 to eight in one quarter inch. Obverse face finely striato-granu- 

 late, ornamentated with numerous irregularly scattered small 

 tubercles. 



Of the several species of Glauconome found in the Carboniferous 

 limestone strata of the West of Scotland, this form is the most 

 robust in its manner of growth. In size it corresponds with 

 G. grandis, M'Coy, but is easily distinguished from that species 

 by the smaller • number of cells between the branchlets, and by 

 its strongly tuberculated keel. From G. retroflexa it is dis- 

 tinguished by its stouter branches, the wider position of the 

 tubercules on the keel, and the more numerous cells in proportion 

 to the branchlets. 



Localities: Lower limestone shales of the Beith and Dairy 

 districts in Ayrshire, in fragments of fronds from one to three 

 inches in length. Brockley, near Lesmahagow, in fragments in 

 the lower limestone shale. Upper limestone series, Gillfoot, 



