(92) 
the same specific group. In the absence of most of the cited specimens 
of C. abbreviatum, no further remark can here be ventured on the 
asserted structural discrepancy between it and C. flaccidum, than that 
there seems to be a considerable diversity, in those species of the section 
before us in which the cortical layer has been observed to be cellular, in 
the distinctness with which this is exhibited. It is possible then that in 
this respect as well, the present small but in all respects distinguished 
cluster, shall prove to illustrate the entire resolution of ‘‘ Synechoblastus.” 
——12. C. nigrescens (Huds.) Ach. Trunks. Northern and middle 
states to Virginia. South Carolina (Mr. Ravenel). Illinois (E. Hall). 
California (Bolander). Var. leucopepla is a smaller lichen, with white 
pruinose apothecia, and rather longer spores, in which last respect only 
it differs from v. lewcocarpa, Babingt., of Tasmania; and both may well 
be compared with the Spanish v. cesia, Ach. It (v. leucopepla) is com- 
mon at the South, from South Carolina, (Mr. Ravenel) to Lousiana (Hale) 
and Texas (Mr. Wright) and has even occurred on the south shore of 
Massachusetts (Mr. Willey). More distinct from the type of the species 
is the rupicoline sub-sp., C. ryssolewm, Tuck. Lich. Calif. p. 34, growing 
on granitic rocks from New England to Virginia (Tuckerman) in New 
York and New Jersey (Mr. Austin) and in the mountains of North Caro- 
lina (Mr. Curtis) the ovoid or at length cymbiform spores of which 
(18-277™™., but reaching 32™™™- long) contrast with the long-fusiform ones 
(46-57"™™., but reaching 70™™™- long) of the bark-lichen, exactly as we 
have seen above in the analogous spore-history of C. flaccidum. 
Sect. 3.—EUCcOLLEMA. 
13. C. coccophorum, Tuck. Obs. Lich. 1. ¢. 5, p. 385. On the earth; 
Valley of the Rio Grande, Texas (Mr. Wright). Oakland, California 
(Mr. Bolander). Spores (now biscoctiform, and constricted at the middle) 
never exceeding the bilocular stage ; 11-18™™™- long, and 7-9™™™. broad. 
The habit is quite that of species associable with C. pulposum; and the 
spores (now comparable, except in size, with those of Buellia atroalba) 
offer nothing to distinguish them from decolorate expressions of the 
coloured type. ——14. C. Texanum, Tuck. Suppl. 2, 1. c. 28, p. 200. 
Bark of trees in the valley of the Rio Grande, and on the earth in the 
prairies of the Blanco, Texas (Mr. Wright). On calcareous earth, 
Alabama (Mr. Peters). Spores ovoid-ellipsoid, rarely constricted at the 
middle, not exceeding the bilocular stage; 9-15™™™- long, and 5-8"™™™. 
broad. Close to C. pulposum, and it may be too close; but the narrowed, 
radiant lobes of the described lichen are rather comparable with those 
of C. laciniatum, Nyl., and C. cyrtaspis; and suggest as well the Irish C: 
multipartitum, Sm. The relation of the little group of European lichens 
(C. stygiwm (Scheer. pr. p.) C. Laureri, Flot., Synechobl. Miilleri, Hepp) 
now associated, with the species last named, under Synechoblastus, by 
authors, to Eucollema and C. multifidum, is not unlike that of the present 
