DIANEMA.] MARGARITACE^. 205 



profuse, consisting of pale yellowish-grey, straight, rigid, slender 

 threads, 0-5 to 2 /* thick, forking at an acute angle, connected 

 with each other at the opposite ends, or fasciculate, without free 

 branches, minutely papillose on one side, attached above and 

 below to the sporangium-wall by the suddenly acuminate 

 extremities. Spores pale yellowish-grey, closely reticulated over 

 the greater part of the surface with raised bands, forming a 

 border 0-5 to 1 ^u. broad, the remaining part marked with broken 

 or very loose reticulation, 6 to 8 /u, &a,m.—Comii/via depressa List., 

 in Journ. Bot. (1891), p. 265. 



Plate LXXIV., B.— a. sporangium, x 20 ; S. eapillitium, showing attach- 

 ment of the threads to the base and upper wall of the sporangium, and 

 spores, X 280 ; c. eapillitium and spores, x 600 (England). 



A description of this species was given in Journ. of Botany, I.e. 

 under the name of Comuvia depressa, on account of its affinity with 

 Margarita metalUca, which at that time was included in the genus 

 Comuvia. Dr. Eex having since established the genus Dianema for 

 the closely allied American species, it is here adopted as in every 

 way the more appropriate position for this species. 



Hab. On dead wood.— Batheaston, Somerset (B. M. 2, 3, 4, 5, 96, 

 300) ; St. Catherines (B. M. 19a) ; Eudloe, Wilts (B. M. 19) ; Lyme 

 Regis, Dorset (L:B.M.169). 



3. D. corticatiim Lister, sp. nov. Plasmodium pink. Sporangia 

 hemispherical, 1 mm. diam., more often forming ring-shaped, 

 elongated, or netlike plasmodiocarps 3 to 12 mm. long, shining or 

 opaque, chestnut or lurid brown ; sporangium-waU ochraceous-olive, 

 composed of two layers, the outer densely granular, the inner 

 hyaUne. OapUlitium somewhat sparse, consisting of simple or 

 acutely branching, slender, brown and pale threads, 0*5 — 1"5 /i, 

 diam., often with distant beadlike thickenings, either nearly smooth 

 or marked with a single prominent spiral band, occasionally for 

 a short distance with three bands ; the threads are attached 

 above and below by very delicate extremities to the sporangium- 

 wall. Spores brownish-pink in mass, nearly colourless when 

 highly magnified, subelliptieal, adhering in clusters of 4 to 6, 

 minutely warted on the outer side, 10tol2x8to9;u, diam. 



Plate LXXVIL, B. — ». plasmodiocarp, x 20 ; &. eapillitium attached to 

 fragment of sporangium- wall, and clustered spores, x 280 ; e. eapillitium, 

 X 600 ; d. spores, x 600 (Norway). 



This species was found in some abundance on rotten planks at 

 Sande, Norway, September, 1894, in company with Licea flexuosa, to 

 which it Isears a strong resemblance under a pocket lens. It holds an 

 intermediate position between the genera Dianema and Prototrichia, 

 having the general features of the former, but exhibiting in some 

 sporangia the spiral bands on the eapillitium characteristic of the 

 latter. It differs from the species hitherto comprised in both genera 

 in the more substantial sporangium-wall and in the clustered spores. 

 The description of Periehcena Krupii Bacib. (see p. 201) may possibly 

 refer to this species. 



Bab. On rotten wood.— Norway (L;B.M. 174). 



