332 



PROCEEDINGS OF THE 



Cells, eighteen ; pinnules, six in one-quarter inch on either 

 side. 



Locality: Hairmyres, East Kilbride. 



This is a very ^yell marked species; the regular alternation of 

 the pinnules, and the number of cells (two) in the intervals being 

 easily recognisable, even in small fragments. G. grandis, M'Coy, 

 has one cell at the base of each pinnule, and three in the inter- 

 vals; but they do not alternate, and they strongly indent tlie 

 margins. They are, moreover, only half their own length apart; 

 and there are no bipinnate branches. The cells are prominent, 

 and keel indistinct. In G. laxa the cells are elongate, and partly 

 buried by the prominent keel. 



The following table sums up the principal points of distinction 

 between the species: — 



Name of Species. 



G. bipinnata, Phil., 



G. gracilis, M'Coy, 



G. grandis, M'Coy, 



G. pulcherima, ISI'Coy, . . . 

 G. (Diplopora) marginalis, 



G. elegans, 



G. aspera, 



G. flexicarinata, 



G. retroflexa, 



G. laxa, 



G. (Acanthopora)stellipora, 



CD 



o 



P 



3 



►3 



fD 



I. 



o 



i length. 



1^ lengths. 

 2 lengths. 



2 lengths. 



( more than 

 I length. 

 ( more than 

 i length, 

 length. 

 2 lengths. 



alternate. 



opposite, 

 sub-alter, 

 alternate. 



alternate, 

 alternate. 



alternate. 



alternate. 



alternate, 

 alternate. 



All of the above species of Glauc'onome were obtained from a band 

 of limestone shale that lies over the limestone at Hairmyres old 

 quarries, East Kilbride, Lanarkshire. This shale is highly fossili- 

 ferous, and, besides numerous other organisms, it contains several 

 genera of Polyzoa, all of which are in an excellent' state of 

 preservation. These organisms crowd the surface of the various 

 layers of shale, the fronds of the Polyzoa being in a more or less 

 broken up condition. Where the shale is weathered into a soft 

 clay, numerous fragments of these Polyzoa can easily be obtained 

 for microscopic examination, by washing the weathered shale. 



