(58) 
last-named the relations of these plantsto some of the lower and obscurer 
Algee are however expressly noted, and the thought is carried a step 
further in the actual removal of Synalissa, Thermutis, and Lichina to a 
new section (Byssacee@) intermediate between Lichens and Algw proper. 
Still later this section (Byssacee) was extended by Fries (£7. Scan. p. 
291. S. V. S. p. 121) to include also his Collemacee ; and though bur- 
thened with ambiguous, and it has since proved, incongruous elements, 
the removal of which by Montagne (Pl. Cell. Cub. p. 106) may be said to 
have done away with much of the vitality of the section as it certainly 
invalidated its name, — furnishes the historical foundation of the arrange- 
ment which, under various names (Collemacee, Mont. Aperc. Morph. 
Scher. Enum. Mass. Mem. Nyl. Lichenes homeomerici, Koerb. Anz. 
Phycolichenes, Mass. Sched. Stizenb. Homolichenes, Th. Fr.) has since 
generally obtained. 
It is notwithstanding difficult to get at the supposed value and syste- 
matic significance of this arrangement, as apprehended by the authors 
who have, since Fries, adopted it ;—-and the difficulty is, we presume, an 
intrinsic one. Leaving out of sight the more or less gelatinous nature, 
when wet, of the Collemei, which, in this way and to this extent, ap- 
proach some of the lower Alge, and the strict affinity of the Ephebei to 
Stigonema and other groups, still, but perhaps not always to be reckoned 
among Alge, the distinction of the family before us turns wholly on 1) a 
‘similarity’ of thalline structure resulting from acertain, more or less marked 
confusion of the elementary parts, and 2) a general dissolution of the 
gonimous layer ;! and great stress cannot easily be laid on either of these 
family of Parmeliacee; the Lichinee being separated, as by Fries, but appended 
to Spherophoracee. 
1 “Ob gonidia thallo similari inspersa, strato scilicet corticali s. gonimo cum 
medullari confuso.” Mont. Pl. Cell. Cub. p. 105. “£ cellularum stratis ple- 
rumque indistinctis in pulpam similarem confusis” . . . . gonidiis “stratum 
diseretum nullum” informantibus. Koerb. Syst. p. 393. ‘‘Les grains gonidiaux 
sont disposés Tune maniere tout a fait spéciale . . . . le cortex nest repré- 
senté le plus souvent que par un épithalle; . . . ~ Mautres fois par une couche 
de cellules anguleuses, distinctes. Le reste du thalle appartient au systéme 
médullaire et se compose dune substance trés avide @eau (sorte de lichenine) par- 
courue par des filaments tubuleux, ou creusée, dans quelques Collémacés, de cavités 
arrondies contenant des grains gonidiaur; chez @autres enfin tout le thalle est 
formé @un tissu celluleux. Dans les formes fruticuleuses de ce meme groupe on 
observe parfois une axe central constitué par des éléments filamenteux articulés, 
disposés longitudinalement en une faisceau blanchdtre. . . rappelant en quelque 
sorte le cordon médullaire des Usnées. . . . Les espéces dont le thalle est 
formé de tissu celluleux different @ peine, par leur structure intérieure, de quelques 
Lichénacés, mais elles se rapprochent par d'autres caractéres des Collémacés; 
ces derniers se laissent @ailleurs facilement reconnaitre par leur port tout spécial, 
par leur coloration foneée et mate, par leur coupe luisant sous le sealpel (consé- 
quence de leur constitution gélatineuse) par leur grande distensibilité dans Veau, 
