PHYSARUM 83 



41. Physarum nicaraguense Macbr. 



Plate XV., Figs. 7,7 a, 7 b; XVIL, 11 and 11 a. 



1893. Physarum nicaraguense Macbr., Bull. Lab. Nat. Hist. lovia, II., p. 383. 



1894. Physarum compressum Alb. & Schw., List., Mycetozoa, p. 53, in part. 



1910. Physarum nicaraguense Macbr., Fetch, Mycetozoa Ceylon, p. 334. 



1911. Physarum reniforme List., Mycetozoa, 2nd ed., p. 72, in part. 



Sporangia multilobate or compound-contorted, below obconic, 

 gray, ribbed with calcareous thickenings; stem short, fuscous, longi- 

 tudinally wrinkled; hypothallus distinct, black; columella none, al- 

 though the lime massed at the centre of each sporangium simulates 

 one ; capillitium white, densely calcareous, with heavy angular nodules 

 connected with comparatively short threads; spores violet, globose, 

 spinulose, about 12 jn in diameter. 



Ometepe, Nicaragua. Professor B. Shimek. 



This species resembles in some particulars No. 39, especially in the 

 amount of lime present in both capillitium and peridium, in the 

 fluted, sooty stipe, and the rough spores. Mr. Lister once regarded 

 it as the same. Nevertheless, it differs from P. notabile in many 

 definite particulars. In the first place, the sporangia are different 

 in form and habit. They are obconic, nearly always compound, con- 

 volute, or botryoid, in this respect somewhat resembling P. poly- 

 cephalum. Besides, the sporangia are uniformly much smaller, and 

 show constantly the strongly calcified centre, much transcending any- 

 thing seen in P. notabile. The stipe also is peculiar, quite short, an 

 upward extension or sweep of the common hypothallus which is 

 usually very distinct or prominent; and, while the stipe is longitu- 

 dinally wrinkled, it is much less so than in the related species, and in 

 a different way. The spores are about the same in size, but differ in 

 color, in this respect agreeing rather with P. leucophaeum. 



In the Mycetozoa, 2nd ed., I. c, the present species is entered as a 

 synonym of two described by Massee: Tibnadoche reniforrnis Mass., 

 Mon., p. 336, and Didymium echinosporum Mass., Mon. 239. But 

 Massee's description of his tilmadoche is, naturally enough, at vari- 

 ance in every important point with the facts in the species before us. 

 Massee says : ". . . . sporangia deeply umbilicate below, sau- 

 sage-shaped and curved ; the stem elongated slender erect, pale brown ; 



