LEPRALIA. .309 



rows of cells. The aperture is small and circular, with a 

 hollow tubercle on each side. The ovarian capsules are a 

 little punctured, with a perforation on the posterior side. 



11. LEPRALIA QUADRIDENTATA, A. H. Hassall. 

 Hab. Ireland, Hassall ; near Aberdeen, Macgillivray. 



** Wall of the cells granulous. 



12. LEPRALIA GRANIFERA, Dr. Johnston. (Plate XVIII. 

 fig. 69.) 



Hab. On slaty rocks, Holy Island, and Berwick Bay, Dr. 

 Johnston ; Isle of Man, Prof. Forbes ; Cornwall, Mr. Peach ; 

 Saltcoats, Ayrshire, D. L. 



Dr. Johnston thinks this, in some respects, resembles L. 

 tenuis ; it bears some resemblance, also, to L. hyalina, but 

 it has marks that distinguish it from both of them, as will 

 appear from the following excellent observations with which 

 Mrs. Gatty has obligingly favoured me. 



" The varieties of L. gramfera figured in the Plate seem 

 to demand an explanation. The one marked a, was first 

 found on Phyttophora rubens, from Portrune, in Ireland, 

 in 1851, and the second variety, b, was discovered by 

 Dr. Greville the same year, on Phyllophora rubens, from 

 Sidmouth. The horned variety has since been found at 

 Sidmouth also. 



