(90 ) 
this confusion of spore-types in C. flaccidum.—A4. C. cyrtaspis, Tuck. 
Obs. Lich. 1. ¢. 5, p. 387. Trunks, apparently rare at the North, but 
found in Massachusetts (Mr. Willey). It becomes common in the middle 
states and southward; where, as westward, it has the same range with 
the last. The present still appears to me a distinct link in the chain 
which connects C. conglomeratum and C. pycnocarpum. Spores quadri- 
locular, longer than those of C. pycnocarpum; averaging from 16 to 
almost 238"™"™- in length, and 4 to 7™™™" in breadth. ——5. C. laciniatum, 
Nyl. Lime-rocks, Alabama (Mr. Peters). On calcareous rocks, Kansas 
(Mr. E. Hall). Spores scarcely exceeding the bilocular stage in the 
Alabama lichen; but becoming quadrilocular in that from the island of 
Cuba (Wright Lich. Cub. n. 4). Habit of the plant entirely congruous 
with that of C. pyenocarpum, and C. cyrtaspis; and the spores appear to 
confirm the affinity. ——6. C. microphyllum, Ach. Elm bark, Weymouth, 
Massachusetts, (Mr. Willey). Illinois (Mr. Hall). The minuteness of the 
thallus makes its real type less easily discoverable; I incline however to 
regard this as closely approximating, in both European and American 
specimens, to the type exhibited in C. callibotrys, especially as shown in 
C. verruciforme. The plant is thus also brought into near relation (as 
indicated by Scherer) to C. conglomeratum; while its distinctly muriform 
spores suggest at once the not wholly dissimilar ones of C. verruculosum, 
above noticed. ——7. C. callibotrys, Tuck. im litt. ad cel. Nyl., & Obs. 
Lich. 1. c. 5, p. 886. Fere C. coccophylloides, Nyl. Prodr. Nov. Gran. p. 
1? Trunks, South Carolina (Mr. Ravenel). I have noted in the descrip- 
tion of this species that the at first curiously squared spores become at 
length ellipsoid or even oblong-ellipsoid, and either regularly quadrilocu- 
lar, or the spore-cells finally divided (sub-muriform). Together with C. 
coccophyllum and C. verruciforme, Nyl., and C. quadratum, Lahm, the 
present constitutes a natural cluster, or species sens. lat., the evolution of 
the thallus in the best-developed members of which connects it with C. 
pycnocarpum, and no less with C. aggregatum, &c.——8. C. verruci- 
Jorme, Nyl. On Red Cedar, Weymouth, and New Bedford, Massachusetts 
(Mr. Willey). Quite inferior, in its almost crustaceous thallus, to Scher. 
n. 416, which is the type of C. verruciforme, and approaching rather to 
C. quadratum, Lahm, as that is described; but the distinctness of the 
latter is scarcely yet made out. According to Mr. Willey’s observations, 
the squared spores become finally ellipsoid, and regularly quadrilocular, 
as in the last species. ——9. C. leptalewm, Tuck. Obs. Lich. 1. ¢. 6, p. 263. 
Trunks ; New England to Virginia. New York (Mr. Russell). South 
Carolina (Mr. Ravenel). Alabama (Mr. Peters). Louisiana (Hale). And 
collected also, by Mr. Wright, in theisland of Cuba, and in Japan. The 
cluster to which this belongs is represented in Europe by C. aggregatum, 
Nyl., and in intertropical America by C. implicatum, Nyl. (Herb. v. d. 
Bosch. Coll. Lindig.n.749. Orizaba, Mexico, Dr. Mohr) and C. glaucoph- 
thalmum, Nyl. (Coll. Lindig. u. 813) and is associable, by its peculiar habit 
