214 NOTES ON SOME RARE SPECIES OF MYCETOZOA. 



D. EFFusuM var. tenue, n. var. Sporangia sessile, annular, 

 orbicular- depressed, or elongated plasmodiocarps with a central 

 depression ; grey, or glossy brown from the absence of lime. There 

 is often a well-defined line of dehiscence round the upper margin of 

 the sporangium-wall. The sporangium-wall is sparingly beset with 

 minute lime-crystals, or naked. Columella none. Capillitium of 

 slender, flexuose, violet-brown threads of equal thickness, but 

 beaded with dark prominences here and there. Spores minutely 

 spinulose, palish purple-brown, 7-8 /j. diam. 



This form has appeared in extreme abundance among dead 

 sycamore and Spanish chestnut leaves in Wanstead Park, Essex, 

 during last autumn. It is constant in its characters, and I first 

 gathered it in the same locality in April, 1888; the crystals are 

 always scanty, and the capillitium coloured. Considering the wide 

 divergence, in the Wanstead Park gatherings, from the usual type 

 of Diihjmium rjf'aswn, and the absence there of intermediate forms, 

 they would appear to claim specific rank ; but bearing in mind the 

 great variety exhibited by D. eff'usum in sporangia derived from Plas- 

 modia of a common origin, and the near approach of some of the 

 effused forms to the one under consideration, it appears better, 

 for the present at least, to record it as a variety of that species. 

 I propose the varietal name of tenue on account of the constant 

 slender form of the plasmodiocarps. 



CoMATRicHA LURiDA Lister. This species has been abundant 

 during last winter in the locality where it was first discovered at 

 Lyme Kegis in 1890, and where it has been gathered almost every 

 year since that date. It has also been met with sparingly in other 

 parts of the district. It was found in large quantities on dead 

 leaves under hollies at Witley, Surrey, in Oct. 1896, and Mr. E. S. 

 Salmon collected it on dead leaves at Reigate in Jan. 1897. The 

 species is well-marked and constant in its characters, and though 

 difficult to recognize at first from its similarity to sporangia of 

 Lawprodenna iridenm which have lost their iridescent walls, and 

 with which common species it is often accompanied, it is un- 

 mistakable as a mounted object. I know of no other record of its 

 collection beyond those above mentioned. 



C. RUBENS Lister. In addition to the stations mentioned [B. M. 

 Cat. Myc. 123), this species has been found in Eppiug Forest, and 

 also at Witley, Surrey, and was unusually common at Lyme Regis 

 in the winter of 1896-7. Like the species last referred to, it 

 is strikingly constant in all its characters, but, from its minute 

 size and close similarity in colour to the dead leaves on which the 

 sporangia are found, it is easily overlooked. The persistent basal 

 portion of the sporangium-wall appears to be an invariable feature, 

 and renders the position of the species in the genus Coinatricha, 

 rather than in the genus Lamprodenna, a somewhat doubtful one. 



C. TYPHoiDEs var. y. MicROspoRA Lister. A large gathering of 

 this form was obtained on dead sycamore, oak, and bramble leaves, 

 under brambles on the margin of the woods in Wanstead Park, 

 Essex, in Nov. 1896. It is precisely the same form as that from 



