ZOOLOGY AND BOTANY^ MICEOSCOPY, ETC. 887 



composed of false articulations of very unequal length. They consist 

 of a calcareous envelope which, covers the walls of a single rounded 

 central cell, the calcareous envelope being traversed by canals, which 

 are nothing but intervals to allow the passage of prolongations of the 

 central cell which bring it into contact with the surrounding medium. 

 When the false articulations are separated, those which are simply 

 superposed are found to have only a single opening at each end, 

 while those which give birth to two branches have two openings at 

 their upper end. 



New Type of Algse in Stigmaria-coal.*— In the stigmaria-coal 

 of Kurakino in Central liussia, P. F. Eeinsch found algoid structures 

 which he refers to a new type related to the Scytonemeae. They form 

 filaments and flat bands of compound structure without, but less com- 

 plicated within, composed of a semi-transparent orange or yellowish 

 nearly homogeneous substance which does not polarize. These 

 organisms may be referred to three different types : — 



1. Filaments 1-1 "5 mm. long and 0' 077-0 '09 mm. broad, in- 

 dented on one side to one-third of their breadth ; the segments 

 uniform in size, 0"009 mm. broad, closely packed and slightly 

 thickened at the extremity ; the swollen end divided into a number of 

 fine segments. 



2. Plane filaments deeply indented on both sides. 



3. Composed of filaments either quite distinct or only united at a 

 few spots, but much branched dichotomously. The filaments are 

 from O'll to 0*16 mm. long and 0' 045-0 "067 mm. broad, partly 

 entire and partly split into segments. 



The absence of any regular cellular organization, and the peculiar 

 internal structure of the filaments, show that they cannot be palese or 

 other epidermal appendages of vascular cryptogams, to which they 

 present an external resemblance. 



Parasitic Alga-like Plants in Russian Coal.f — In his micro- 

 scopical examination of Eussian coal (Blatter kohl), P. F. Eeinsch 

 found a number of organic vegetable structures, hitherto referred to the 

 epidermis of Lepidodendron, but which he regards as much more 

 probably an alga allied to the Enteromorphege. The greater number 

 of the lamellae of the coal are variously and irregularly perforated, 

 the perforations having a diameter of from • 4 to 1 ' 5 mm. ; they are 

 circular, elliptical, or triangular. Their distance from one another 

 varies between 2 and 4 mm. As many as eight different forms may 

 be distinguished, varying in the size, form, and distance apart of the 

 openings. In all the specimens examined the perforated lamellae 

 constitute the greater part of the coal; between the lamellte is a 

 carbonaceous substance composed sometimes of thin flakes of an 

 amorphous substance inclosing large numbers of Triletes. All the 

 phenomena point to the probability of the plants from which this coal 

 was formed having been water- rather than land-plants. 



* Flora, Ixvi. ^1883) pp 355-60 (1 pi.). 



t Ibid., pp. 823-30, 339-44 (3 pis.). Cf. this Journal, ante, pp. 409, 537. 



