NOTES ON SOME EARE SPECIES OF MYCETOZOA. 213 



in hand, I place it as possibly a form of P. compressum A. & S., but 

 the granules of lime in the sporangium-wall and lime-knots are 

 large for that species. I make this explanation to correct my own 

 mistake, and also on account of the confusion that has arisen with 

 regard to the name. 



DiACH/EA suBSESsiLis Peck. This beautiful species was found on 

 dead bramble-leaves and stems in Flitwick Wood, Beds, on Sept. 8th, 

 189G. Tlie sporangia are about 0-5 mm. diam., subglobose and with 

 an iridescent lustre, either provided with a conical white stalk or 

 sessile, or of plasmodiocarp form. The columella is shortly conical 

 or obsolete. The capillitium consists of a network of violet-brown 

 threads radiating from the columella. The spores have a greenish 

 colour, occasioned by the yellow contents appearing through the 

 pale purplish spore-wall, which is beset with minute spines arranged 

 in a reticulate pattern, as described by Dr. Uex (B. 3/. Cat. Mijc. 92). 

 Some groups of sporangia are entirely destitute of lime, and in this 

 case they are either sessile or have a short black stalk, the columella 

 being reduced to a yellowish membranous tube. The limeless form 

 agrees in all respects, including the sculpture of the spores, with a 

 specimen of Lawproderwa Fuckelianum Kost. var. cracowense Racib. 

 kindly submitted for inspection by Dr. Celakovsky, of Prague. It 

 has a striking bearing on the species named by Dr. Sturgis Coma- 

 tricha ccespitosa, a form without lime, which I suggested might be a 

 variety of Diaclimt T/inmasii (1. c. 92), though the constancy of the 

 long, membranous columella in repeated gatherings makes it pro- 

 bable that it is a distinct species. There is a near relationship 

 between />. Tlwmasii and D. suhsessilis, and, judging from the few 

 gatherings that have been obtained, the difference consists in the 

 orange-coloured stalks and clustered grouping of the papillae on the 

 spores (under high magnification) of the former, as compared with 

 the white stalks, densely charged with white lime-granules, and 

 the reticulate arrangement of the papilhe on the spores of the latter. 

 The peculiar greenish colour of the spores is confined, as far as my 

 observation extends, to D. suhsessilis Peck, D. Thomasii Rex, and 

 Coiiiatriclut ca;spitos(( Sturgis. 



A specimen of the Flitwick gathering has been submitted to Dr. 

 Sturgis for comparison with the American type of D. subsi'ssilis Peck. 

 He considers it identical with the latter species, but has been unable 

 to procure an example of the type, which appears to represent a 

 single gathering, and is now placed in the New York Museum. 



DiDYMiuM DUBiuM Rost. has been abundant this winter in the 

 locality where it was first found at Lyme Regis in April, 1888. 

 I obtained it from near Lyndhurst, New Forest, in Oct. 189(3, and 

 at Witley, Sui-rey, in the same month. Through tlie courtesy of 

 Dr. Celakovsky, juu., I possess part of the original type gathered 

 by Opiz at Hauenstein in 18BG. It confirms my opinion that our 

 English gatherings belong to the same species ; some of these 

 exhibit similar capillitiums and spores, though we find a con- 

 siderable range of variation ; the capillitium is usually more rigid 

 and the spores paler than in the type. 



