54 



other specimens I found the roof apparently not decorticated, but 

 the canals visible, so that this decortication perhaps may be atten- 

 ded on external causes. Later the middle part of the roof gets 

 quite dissolved, more seldom the whole roof. The sporangia I 

 frequently found to be 110 — 140 \i long, occasionally only about 

 90 or up to 150 p, and 35 — 45 ^ broad, seldom even up to 60 p. 

 The thickness apparently is about V3 °f the breadth, or more. 1 ) 

 In f. nana the conceptacles as well as the sporangia themselves 

 are slightly smaller than is general in the above quoted forms. In 

 f. flexuosa they frequently agree with those in the other forms, but 

 on the other hand sometimes a little larger, more distinct and more 

 prominent, the roof up to 350 /j. in diameter, thinner and more 

 easily dissolvable or falling away than in any of the other forms. 

 Hauck 1. c. records the conceptacles to be „flach-\varzenformig", 

 which, so far as I have seen, accords rather better with those of 

 L. crassum. In one of his specimens of f. flexuosa I found some 

 few very little prominent, convex, but in part not sharply marked 

 and in all fully agreeing with typical ones of the present species. 

 In f. corymbiformis I have only seen overgrown conceptacles, which 

 in a median section are of about the same size as in f. typica. 



Overgrown conceptacles in general are to be found only in 

 the peripherical portion of the branches or processes, rather seldom 

 in any greater number. The appear to be proportionalhy most 

 common in the forms fastigiata, intermedia, nana, glomerata and 

 curvirostra. In f. typica they sometimes are rather numerous, 

 sometimes very few or apparently wanting, which appears to relate 

 to the fact that the plant does not probably always develop the 

 named organs, or that the whole roof occasionally falls away and 

 the conceptacle becomes effaced by local formations of tissue, as 

 for inst. in L. glaciale. In f. flexuosa overgrown conceptacles 



*) The sporangia of the present genus altogether appear to be convex-concave 

 and thickest in the middle, and, therefore, the measures of the thickness 

 only are approximate. They appear partly to be thicker partly and appa- 

 rently more frequently thinner in proportion to the breadth than above 

 quoted, but more exactly measures are not to be got without dissecting 

 the sporangia, which, however, may not be required in a systematic point 

 of view, as they also in this respect seem to be rather varying. 



