398 INTRODUCTION TO CEYPTOGAMIC BOTANY. 



of Calicium. It differs, in fact, more in habit than in cha- 

 racter, from Siphula* The spermatia of S])h. comiyressuin 

 are very minute and oblong. In Acroscyphus they are of 

 nearly the same form, but coarser. Sphceroplioron occurs in 

 the cold and temperate regions of both hemispheres, but seems 

 to be very rare within the tropics. The southern hemisphere 

 has a few fine endemic species. Acroscyphus occurs in Peru. 

 One of the most curious genera perhaps of Sphcerophorei is 

 the Cayenne genus Ozocladium (Fig. 85, a). The main thallus 

 is branched and beset with a single row of imbricating, scale- 

 hke apothecia, proliferous at their upper margin, so as to pre- 

 sent a moniliform appearance. Each apothecium is at first 

 closed, but the top soon bursts hke a veil, disclosing a disc 

 consisting of linear asci, filled with a single row of numerous 

 pale hyaline sporidia, like some species of Hypocrea. 



6. LiCHiNEi, Mont. 



Thallus gelatinous, erect, or horizontal ; gonidia forming 

 moniliform chains or fissiparous ; excipulum of the same 

 nature as the thallus. 



435. The difference of substance between the gelatinous 

 CoUemals, and the more or less rigid Lichens, is the only cha- 

 racter which separates them ; unless it be the peculiar modes 

 of arrangement assumed by the gonidia. I cannot, therefore, 

 assent to this distinction, though there are two distinct 

 groups, belonging respectively to the gymnocarpous and an- 

 giocarpous type. Lichma has the habit of Sphcerophorei, 

 and differs principally in its substance. Its habitat on 

 exposed marine rocks, often dripping with salt water, and as 

 suddenly dried up, requires in it some element very patient of 

 change. There is no true perithecium, and the sporidia are 

 very different from those of Sphcrn'ophoron, being quite 

 colourless, and resembling more those of Fungi ; indeed, but 

 for the gonidia it must be associated with them. Paulia 

 assumes the foliaceous form, and is analogous to Endocarpon. 



* The old perithecium, when divided, resembles very closely the cup 

 of some acorn. The orifice is circular and quite even, the inner surface 

 perfectly smooth, with an orbicular darker disc at the base. 



