DERMATOCARPON] DERMATOCARPACEiE 269 



2. D. aquaticum A. Zahlbr. Krypt. Exsicc. n. 652 (1901). — 

 Thallus spreading, polyphyllous, rather thick and coriaceous, the 

 lobes crowded, flaccid, crenate and incurved, tumid, ascending in 

 the centre, more flattened at the circumference, green wlien wet, 

 pale to brownish when dry, the under side naked, pale at first 

 then darker coloured. Perithecia minute, innate, sometimes 

 confluent, with slightly prominent brown ostioles ; spores 8 in 

 the ascus, oblong or ellipsoid, 0,010-16 mm. long, 0,006-9 mm. 

 thick. — Lichenoides imhricatum luridum Dill. Hist. Muse. p. 224, 

 t. 30, f. 128 (1741). Lichen aquaticus Weiss PI. Crypt. Fl. 

 Goett. p. 77 (1770) ; Engl. Bot. t. 594. L. fluviatilis Web. 

 Spicil. El. Goett. p. 265, t. 4 (1778) ; With. Arr. ed. 3, iv. p. 67. 

 L. Weheri Ach. Lich. Suec. Prodr. p. 142 (1798). Endocarjjon 

 Weberi Ach. Meth. p. 128 (1803); S. F. Gray Nat. Arr. i. 

 p. 501 ; Hook. El. Scot. ii. p. 45 ; Grev. El. Edin. p. 329. 

 E.fluviatile DC. El. Er. ii. p. 413 (1805) ; Mudd Man. p. 266; 

 Cromb. Lich. Brit. p. 108; Leight. Lich. El. p. 410; ed. 3, 

 p. 442. E. miniatum var. aquaticum Schaer. Spicil. p. 60 (1826); 

 Hook, in Sm. Engl. El. v. p. 156; Tayl. in Mackay El. Hib. ii. 

 p. 98. 



Exsicc. Larb. Lich. Hb. n. 358 & Lich. Csesar. n. 95. 



Approaches var. comiMcatum of the preceding species in the size 

 and form of the thalline lobes, but is well distinguished by its thicker 

 coriaceous character and by the habitat. The lobes, usually rather 

 large and rounded, are occasionally only from 1 to * 5 cm. in width 

 and deeply cut and laciniate. 



Hah. On rocks and stones in streams and lakes. — Distr. Rare, but 

 widely distributed, chiefly in upland districts. — B. M. East coast of 

 Jersey ; Saints Bay, Guernsey ; St. Breock, Cornwall ; River Teign, 

 near Keston, Lydford, the Dart River and Ivy Bridge, Devon ; Tewy 

 Llandyssiel, Cardiganshire ; Harlech Castle and Barmouth, Merioneth ; 

 Ham, Staffordshire ; Windermere, Westmoreland ; Eglestone and 

 Teesdale, Durham ; Kincardineshire ; Loch Lomond, Dumbartonshire ; 

 Appin, Argyll ; Loch Dochart, Loch Tummel and shores of Loch Tay, 

 Killin, Perthshire ; shores of Loch Linnhe, Invernessshire ; Killarney, 

 Kerry. 



Var. euplocum A. L. Sm. — Thallus coriaceous, minute, mono- 

 phyllous, affixed to the substratum by a central point, deeply 

 lobed, the margins crisped and recurved, olive-green when moist, 

 greyish or brov/nish when dry. — Lichen euplocus Ach. Lich. Suec. 

 Prodr. p. 141 (1798). Endocarpon euplocum Ach. Meth. p. 127, 

 t. 3, f. 4 (1803) ; Borr. in Engl. Bot. Suppl. t. 2602, f. 2 ; Hook, 

 in Sm. Engl. El. v. p. 157 ; Leight. Angioc. Lich. p. 12, t. 2, f. 3. 

 E.fluviatile var. euplocum Mudd Man. p. 266 (1861); Leight. 

 Lich. El. p. 411; ed. 3, p. 443. E. miniatum var. euplocum Wahlenb. 

 El. Suec. p. 875 (1826); Cromb. Lich. Brit. p. 107. Verrucaria 

 euploca Borr. in Engl. Bot. Suppl. I. c. text (1831). 



A minute variety of the species bearing the same relation to it as 

 var. leptophyllum does to D. miniatum. 



