406 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



while Phacopsis and Celidium bear spermatogonia. These 

 parasitic genera, however, are not the more typical forms of 

 the group, but the genus Coccocarpia, which comprises cer- 

 tain species separated from Lecidea, and which differ from 

 that genus in the total absence of any excipulum. The 

 nucleus is, according to Montague,* at first inclosed in the 

 medullary stratum, and at length erumpent. The thallus is 

 between membrana,ceous and tremelloid, and remarkably 

 tomentose beneath. The fruit of Collemals at once distin- 

 guishes them. It is to be observed that Tulasne (M(^m., p. 

 127) considers the apothecia even of this genus parasitic, but 

 he is not borne out by other authors. Their asci and sporidia 

 (Fig. 81, 6) resemble those of some minute Sphcerioi. Coc- 

 cocarpia occurs in tropical America, the Philippines, and other 

 islands of the Pacific and Atlantic, but not in Europe or tem- 

 perate North America, unless Endocarpon pidchellum be 

 really a Coccocarpia, as seems most probable. The parasitic 

 genera occur in most parts of Europe and of North America, 

 extending as far southward as central America, but not ap- 

 parently in the southern temperate zone. 



6. COLLEMACEI, Fr. 



Frond gelatinous, containing moniliform threads of minute 

 gonidia, or large ones arising by fissiparous division. Fruit 

 apothecioid. 



443. If Coccocarpia be indeed autonomous, we have an easy 

 transition through that genus to Collemals ; at any rate, if they 

 are to be excluded from Lichens, Hydnum gelatinosum might 

 as justly be excluded from the genus in which every one is con- 

 tent that it should remain, or TremelUni from Fungi. They 

 are in all essential points Lichens, and to remove them is only 

 to draw off the attention from generals to particulars. In 

 most species of true Collema, there is less distinction of sub- 

 stance than in other Lichens, the whole seeming to consist of 

 medullary tissue, confused with the cortical and gonimic ; but 

 in C. cldoromelum and hallatum (Fig. 79, c)-f- there is a dis- 



* Ann. d. Sc. Nat., s^r. 2, v. 16, p. 122. 



t This is not the same i^lant with Lepiogium hullatum, Mont., bnt 

 that which is figured by Swartz. 



