(71 ) 
refer again, at this place, to higher types which have been elsewhere 
considered, it appears probable that several semi-crustaceous forms, 
mostly of recent discovery, whether referred to Collema or Leptogium, 
have, to say the least, equal claims to rank as Pannarie; and owe indeed 
the position they now hold mainly to the circumstance that the spore- 
history of Pannaria, though not without illustrations of development 
beyond the unilocular or simple stage has not yet been conceived as em- 
bracing the multilocular or muriform one. 
And we are far from leaving Pannaria in the remote distance even 
when reaching what are now generally taken for true Collemeine types. 
It is perhaps scarcely to be doubted, from the point of view at least 
of the present treatise, that the small group of crustaceous lichens rele- 
gated by Acharius to one end of his Collema (sect. Placynthiwm, Ach.) 
is in fact mostly Pannariine. But the corresponding groups in the 
arrangement of Nylander, those namely which constitute for him the 
lowest exhibitions of Collemeine structure (SYNALISSA maz. p. Nyl., & 
PYRENopSIS, Nyl.) are themselves, with all the advance of knowledge, 
not wholly free from ambiguous elements; —the reference of such forms 
as Pannaria Schereri, Mass., to Pyrenopsis rather than to Pannaria, 
appearing to be determined by habit more than by any clear criteria of 
structure, and even habit being much at fault in such as Pyrenopsis 
Flotoviana, Nyl. (Pannaria Nyl., olim. Biatora, Th. Fr. Verrucaria, 
Hepp). If however, comparing with Pyrenopsis the scarcely discrepant 
structure of Synalissa polycocca, Nyl. (Syn. p. 96) we follow this author’s 
plain indications, and subsume Pyrenopsis under Synalissa, there is no 
doubt that the type of the last (S. symphorea) is sufficiently Collemeine. 
Too much so possibly for a satisfactory association with the inferior lichens 
thus brought into connection with it! 
At this point it becomes then evident, if it were not before in Hnchy- 
lium (Mass.) Koerb.,' that we are approaching so closely to a new section 
1 Enchylium, Mass. Mem. p. 93, is constituted of H. synalissum (Synalissa 
symphorea (DC.) Nyl.) and a crustaceous FE. affine, Mass., for which last the genus 
is retained by Koerber. The medullary elements very sparing and imperfect in the 
specimens examined by me of £. affine (Mass. Ital. n. 312. Koerb. herb. Rabenh. 
Lich. Eur. 0. 259) and according to Koerber the plant ‘‘unterscheidet sich von” 
Psorotichia (Pyrenopsis) “eigentlich nur durch die vielsporigen Schlduche.” 
Parerg. p. 433. The reddish tinge so commonly characterizing the outer cells of 
Pyrenopsis is yet wanting here; and Nylander has given expression to a different 
view. ‘ Observetur obiter” he says (Bot. Zeit. 1861, p. 337) ‘‘ Enchylium affine esse 
Omphalariam.” And it adds to the evidence of the mutual approaches of these 
ill-defined groups, that while Massalongo referred to Omphalariee both Synalissa 
(symphorea) and Enchyliwm, Koerb., Nylander places the latter and Koerber the 
former in closest proximity to Pyrenopsis.—— Omphalaria decipiens, Mass., is 
referred to Pyrenopsis, at the place last cited, by Nylander: but very perfect speci- 
mens (Arnold in herb. Krempelh.) suggest perhaps a higher position; as Koerber 
has indicated. (Parerg. p. 431). 
