VINE : CAKBONIFEROUS POLYZOA. 333 
The range of R. rhombiferum I have not such a wide record of, 
but it is generally present in Shales where the other species is 
found. 
The following table will show the range of other species de- 
scribed as found in North Yorkshire. I have prefered, however, 
to mark only those that are in my own cabinet. 
Glauconome, Goldfuss. 
1826. Genus established by Goldfuss, but Munster described as 
Glanconome species of Cellaria. 
1839. Genus revised by Lonsdale, Type of the Genus Glauconome 
disticha, Goldfuss. Stem, stony, thin, elongated oval, 
branched ; cells disposed longitudinally and alternately, 
in rows, over half the surface, the other half straited 
longitudinally." — Lonsdale, Silurian System, p. 676. 
1. Glauconome maryinalis. Young & Young, Drplopora mar- 
ginalis. Sub-Genus, Y. & Y. Proceedings of Glasgow- 
Nat. Hist. Soc, 1875, Plate iii., Fig. 14—21. 
This is the most delicate species of the Genus, and the 
branching is very different from that of other species of Glau- 
conome. There are no pinnules, and the branches strike off at 
wide intervals either laterally or as bifurcations. There is a 
mesial ridge between the marginal cells, and this bears a tubercle 
between each cell. There are also small cells below the larger 
one, and the thin marginal line which separates them is often 
broken away, thus giving to the cell a kind of pyriform structure. 
Locality : — Very rare in the Shales of Hurst, Yorkshire. 
2. Glauconome stellipora. Young & Young. PI. xvi, Fig. 1. 
Acanthopora stellipora. Y. & Y., Sub-Genus. Pro. of Nat. 
Hist. Society, Glasgow, 1875. G. stellipora. Y. & Y. 
Quart. Journ. Geol. Soc, 1874, PI. xi, Fig. 5-11. 
This species is rather abundant in the Shales, and also in the 
Limestone. The stem has a less angrdar appearance than the 
typical species, owing to the crushed state in which they are 
sometimes found. The mesial ridge is more frequently straight 
than sinuous, but the fine beading of the ridges, and the other 
