

M. Foalie. Contribution IL 



43 



L. intermedium f. nana. The form globulata aometimes ap- 

 proaches rather much the last named form when the centre 

 is solid and the branehes much anastomosed upwards, and 

 is difficult to distinguish without microscopic examination, 

 but that is, however, seldom. L. norvegicum has a smooth sur- 

 face but L. intermedium is general! y provided with local, sca- 

 ly thickenings on the surface and consequently uneven. 



Some of the specimens collected in the beginning of 

 September were provided with a iramber of sm a ll and shal- 

 low holes, scarcely perceptible to the naked eye, partly oe- 



* 



cupying a rather sharply defined zone below the tip of the 

 branehes, partly more scattered. Besides 1 also found some 

 small, little prominent and slightly convex eminences togeth- 

 er with the holes. These I suppose to be the superficial 

 conceptacles of sporangia. the former w T ith the roof fallen 

 off and empty, and the latter also emptied. In one of the 

 supposed conceptacles I found a single body about 100 \k 

 long and 30 \k thick which perhaps may have been a spor- 



angium. 



Lithothamnion colliculosum nob. 



L. fronde crustacea, arcte adnata, obscure rosea; crustis tennis, 

 0.5—1.5 mm. crassis, solitariis vel conplnribns inter se adjacentibus mar- 

 ginibui in contactu compresso-elevatis, snperficie subæquaK, tnberculis 

 et ramis brevissimis (usque 4 mm. altis), æqualibus vel apicems versus 

 subattennatis vel incrassatis instructa, apicibus obtusis vel rotundatis ; 

 conceptaculis sporocarpiferis elevatis, conicis, acutis, conceptaculis spo- 

 rangiferis demum innatis ; sporocarpiis pyriformibus vel ovatis vel inter- 

 dum subglobosis, 45—120 /x longis, 20—60 f± crassis. Tab. 3, fig. 1. 



The plant covers smaller stones, forming a thin crust 

 which is closely and firmly adherent to the substratum and 

 pretty uniform in thickness, 0.5 — 1 or sometimes untill 1.5 

 mm. When elder it becomes more or less densely provided 

 with small tubercles, or short, simple branehes not exceeding 

 4 mm. in hight, terete, either cylindrical or tapering, or 



■ta* 



