476 W. C Sturgis — Type- Specimens of Myxomycetes. 



(PI. LXI, fig. 21a.) A somewhat similar instance of compound papillae 

 was noted by Rex in the case of Diachcea Thomasii^ Rex. (Proc. 

 Acad. Nat. Sc. Phil., 1893, p. 368.) 



DiACH^EA suBSESSELis, Plc., Rep. XXXI, p. 41, 1878. Peculiar in- 

 terest attaches to tlie type-specimen of this species since no accurate 

 description of it has ever been published. Fortunately it is so well- 

 marked a species that the original brief description has proved suffi- 

 cient to enable later investigators to identify it with a fair degree of 

 certainty. That Rex had seen the type, seems evident from the 

 accuracy with which he described the episporic markings character- 

 istic of the species (1. c, p. 368. Cf. Lister, Mon. p. 92). Lister has 

 described it at some length on the basis of a specimen collected by 

 him in September, 1896, in Bedfordshire, England, which agreed 

 with the original description and possessed spores marked as 

 described by Rex. A portion of this specimen was sent to me by 

 Mr. Lister. In January, 1899, I collected it at Bonchurch, Isle of 

 Wight, and in the following August I made a small gathering of it 

 at Poquonock, Conn. All of these specimens are identical with one 

 another and with the type. Inasmuch as Lister's description of the 

 species may not be accessible to most American students, it may be 

 well to describe briefly the salient features of the type-specimen. 

 They are as follows : Sporangia subglobose, 0.6-0.6"'°^ in diameter, 

 sessile or stipitate. Stalk, when present, very short, robust, taper- 

 ing, filled with white lime or dark with included refuse matter. 

 Wall membranous, hyaline, slightly iridescent, splitting irregularly 

 from above. Columella pulvinate, short-conical, or sometimes almost 

 obsolete. Capillitium dark violet-brown, paler below. Spores violet- 

 brown, 9.3-1 1.2/A in diameter, marked with an irregular, broken net- 

 work, composed of minute warts and covering the greater part of 

 the surface. (PI. LXI, fig. 20.) Hah. on dead leaves. 



The sessile or short-stalked habit of this species, and the peculiar 

 episporic markings, are quite sufficient to distinguish it from any other 

 Diachcea. It is apparently rare in this country, as Macbride makes 

 no mention of it. I am unable to detect the greenish tint said, by 

 Lister, to be characteristic of the spores of this species. (Journ. of 

 Bot., Vol. XXXV, p. 213, 1897.) 



DiDYMiuM oxALiNUM, Pk., Rej). XXVIII, p. 54, 1875, and Rep. 

 XXXI, p. 57, 1878. No specimen bearing this name is now to be 

 found in the collection. In his Thirty-first Report, p. 57, Peck 

 remarks '■'■ D klyynhmi oxalinmn, Pk., is probabl}' only a form of Phy- 

 sarum cinerettm, and is therefore omitted." The original descrip- 



