LAMINARIACEuE OF ORKNEY 285 



plant-forms. The finest specimens strew the beach in June and Jiily, 

 when the new season's lamina has reached its maximmn growth. The 

 stout stipe is usually only 12-18 inches in length, and not more than 

 10 mm. in diameter, usually less. A point of interest is seen in the 

 fact that many individuals, not different so far as can be seen fi'ona 

 others, yet have mucilage-ducts in the stipe — a feature which has been 

 largely utilized in delimiting " species." Interest also centres in the 

 peculiar corrugation of the fronds ; the " bullation " as it was termed 

 by older writers who only knew plants of quiet harbours, with undu- 

 lated " midrib " region and lateral waved folds or " bullse " of Gmelin, 

 and Stackhouse (1795). All stages in the intensity of such corruga- 

 tion may be seen in one fine specimen, the amount being greater at 

 the base of the lamina and passing into a close system of irregular 

 corrugations, which, in the limit, extend right up to the margin of the 

 lamina. A fine lamina 8 inches or more in width, corrugated finely 

 and closely right up to the straight margin, resembles a piece of 

 wrinkled thick leather-belting, and is like no other British plant. 

 Smaller foT-ms, similarly corrugated, from exposed shores of the Faeroes, 

 have been distinguished as var. linearis Borgesen (1903) ; but there 

 is nothing "linear" about these fine plants, again Avholly different 

 from the general illustrations of the type, as for example the feeble 

 specimens of the Phyc. Brit. pi. 2S9, with no bullation at all. 



NEW OR NOTEWORTHY FUNGI.— Paet VI. 



Br W. B. Grove, M.A. 



(Plate 550.) 



This notice of New or Noteworthy Fungi is a continuation of 

 Part V, which appeared in the Journal of Botany in July and August, 

 1916. The new British fungi contained in the list owe the greater 

 part of their interest to the exceptional keenness of sight possessed by 

 Mr. D. A. Boyd, of Saltcoats, Ayrshire, by whom most of them have 

 been discovered. That part of Scotland is exceedingly rich in Fungi 

 Imperfecta There are also included a few species discovered by the 

 late Dr. J. W. Ellis, of Liverpool, who sent them to me shortly before 

 his much lamented death. The Birmingham Natural History Society 

 has kindly made a grant, from the Endowment of Research Fund, 

 towards defraying the cost of the plate. I owe thanks also to Miss 

 E. M. Wakefield, of Kew, and others, for help in various ways. 



ASCOMTCETES. 



253. Mycosphaerella Cydoniae, sp. n. 



Maculis nuUis. J\'rithcciis hypopliyllis, in greges parvos rotun- 

 datos digestis, rarius sparsis, ca. 100 /it diam., subglobosis, nigris, nitidis, 

 immersis, dein pai)illa crassa emergentibus ; contextu e cellulis laxis 

 atro-fuscis in;t^quallbus confiato. Ascis oblongo-cylindricis v. svibcla- 

 vatis, utrinque obtusissimis, aparaphysatis, fasciculatis, ca. 45 x 5 ^ ; 

 sporidiis plus minusve oblique monostichis, subinde parte superiore 



