PHYSARUM.] ENDOSPORE.E. 61 



red or reddish-brown. Sporangium-wall membranous, with dense 

 innate clusters of orange lime-granules. Colurnella none. Capil- 

 litium a network of hyaline threads with frequent triangular 

 membranous expansions at the axils of the branches ; lime-knots 

 angular, branching, often confluent, orange-red or orange-brown. 

 Spores pale violet-brown, spinulose, S to 11 /x diani. Host., MOIL, 

 p. 104 ; List., in Journ. Bot, 1891, p. 259, PL 308, fig. 2; Mass., 

 Mon., p. 302 ; Blytt, Biclr. Norg., Sop. iii., p. 4. 



Plate XXIII., A. a. sporangia, x 20 ; I. capillitium and spores, x 280 ; 

 c. spore, x 600 (Germany : Rostafinski's type). 



B. a. sporangia, x 20 ; b. capillitium, with fragment of sporangium- wall 

 and spores, x 280 ; c. spore, x 600 (S. Carolina : Cooke's type of P. auri- 

 gcalpiwni). 



The specimen sent by Mr. Wingate to Mr. Massee under the name 

 Leocarpus squamulosus (L:B.M.38) so closely resembles P. rubiginosum 

 that it appears to be an American form of that species ; it agrees with 

 the Strassburg type in the capillitium and spores, and differs only in 

 the more glossy sporangia, which are brown in colour instead of deep 

 red. Two other specimens are difficult to locate. One from Dr. 

 Harkness, Blue Canon, California (L:B.M.38), named in Phillips's coll. 

 Jiiiclhainia inauntta, has subglobose sporangia 1 to 1*3 mm. diam. ; the 

 sporangium-wall is scaly, and pale yellow with a faint reddish tinge ; 

 the capillitium is a network of hyaline threads, with abundant large, 

 branching, pale yellow lime-knots ; the spores measure 8 to 10 /z diam. 

 The other from Aiken, S. Carolina, named in Ravenel's collection 

 Cieiikoic 'sk<<i r< tn-ulnta (B. M. 991), is a deep orange branching plasmodio- 

 carp ; capillitium a network of hyaline threads, with large, branching, 

 pale yellow lime- knots ; spores 7 to 9 /x diam. This specimen has a 

 strong external resemblance to Cienkowsltia reticulata, oui it has not 

 the rigid yellow hyaline capillitium threads with hooked braiichlets and 

 the flat lime-plates of that species. Should further gatherings confirm 

 the characters of these two specimens they might deserve specific rank, 

 but at present they are retained under P. rubiyinosum, to which, not- 

 withstanding the pale colour of the lime-knots, they appear to be most 

 nearly allied. 



The specimen B. M. 863 is part of the type of Physarum auriscalpium 

 Cooke ; another part is in the Kew Herb. It is numbered 1854 in 

 Ravenel's collection from the Sautee Canal, South Carolina, and was 

 described in Myx. U.S.A., Ann. Lye. N. H. New York, vol. xi. (1877), 

 p. 384. It presents the following characters : Sporangia sessile, or 

 with an almost obsolete stalk ; subglobose depressed, gregarious, orange 

 red ; sporangium-wall of two layers, the outer densely charged with 

 orange lime-granules and separating in scales from the membranous 

 grey inner layer ; columella none ; capillitium of large, branching 

 orange lime-knots, with few connecting hyaline threads. Spores dull 

 violet brown, minutely warted, 10 to 12 ju, diam. The specimen repre- 

 sents a single gathering, and the point in which it differs chiefly from 

 Physarum rubiginosum Fries is the Badhamia-like capillitium, but 

 judging from Dr. Cooke's description it would appear that in the 

 sporangia examined by him the hyaline threads were sufficiently 

 developed to include the species in the genus Physarum ; in other 

 respects there are no characters by which it can be defined as distinct 

 from P. rubiginosum, and, provisionally at least, it appears better to 

 place it as a form of the latter species. 



