Lamproderma 171 



Sporangia globose, blue or bronze; capillitium 

 dark throughout; spores 10-12 n, with large, 

 scattered spines. 3. L. muscorum 



Sporangia globose or obovoid, more often irides- 

 cent blue or purple; capillitium usually pur- 

 plish with pale tips; spores ll-14;u. 4. L. columbinum 

 Sporangia globose or obovoid, blue or brown; 

 capillitium pale throughout or darker with 

 pale tips; spores in typical examples 8-10 /x. 5. L. violaceum 

 Sporangia silvery, spotted with black; capillitium 



pale. 6. L. Gulielmae 



Spores more or less reticulate. 



Spores reticulate with raised bands. 7. L. cribrarioides 



Spores marked with a close, imperfect reticulation of 

 raised bands or rows of warts, or spinulose, or mi- 

 nutely warted all over. 8. L. atrosporum 



1. Lamproderma arcyrionema Rost. Mon. 208. 1874. 



Comatricha Shimekiana Macbr. Bull. Nat. Hist. S. U. Iowa 2: 380. 1893. 

 (N. Y. B. G. no. 9825, type material.) 



Plasmodium watery white (Lister). Total height 1 to 2 mm. 

 Sporangia gregarious, globose, stalked, erect, 0.4 to 0.6 mm. diam., 

 steel-gray or bluish, iridescent; sporangial wall membranous, pale 

 purple, falling away in large fragments, persistent as a collar at 

 the base of the sporangium. Stalk subulate-setaceous, about 1 

 mm. high, black, shining. Columella slender, smooth, cylindri- 

 cal, attaining about one third or one half the height of the sporan- 

 gium, suddenly dividing at the apex into the few primary branches 

 of the capillitium. Capillitium of purplish brown or black 

 threads arising from the apex of the columella, at first stouter and 

 branching, then more slender and anastomosing to form a close, 

 dense network, with very short, free ends. Spores pale lilac-gray, 

 faintly warted, 6-8 /x diam. (Plate 16, fig. 9.) 



Type locality: Poland. 



Habitat: On dead wood. 



Distribution: Common and abundant throughout North 

 America. 



Illustration: Lister, Mycetozoa ed. 3. pi. 129. 



This species often forms large colonies, and is remarkably 

 constant in all collections, so that there are no variations of any 

 importance, and no approaches to other species of the genus. 

 The densely netted, persistent capillitium is like that in the genus 

 Arcyria, although not expanding. The divided columella is char- 

 acteristic of the species. 



