(151) 
hue of the content of these central cells is attributable to chlorophyll, 
as the cells therefore are describable as a kind of gonidia (De Bary 1. ¢. 
p. 270. Schwend. 1. c. p. 173). In Cystocoleus however the peripherical 
thread-cells with colourless content, answering to the ‘medullary’ fila- 
ments of Cenogonium, are few (commonly five to six) in number, and 
blackish-brown ; and they coalesce into a close integument, sheathing the 
central column. 
Cystocoleus rupestris (Pers.) Thwaites 1. ¢., has occurred, in this 
country, only in North Carolina (Rev. Dr. Curtis). These specimens, 
determined already by Dr. Curtis as the plant of Persoon, prove exactly 
similar, in the analysis, as above given, to the foreign ones. 
Fam. 3.—LECIDEEI. 
Thallus crustaceus, aut effiguratus aut rarissime papilloso-ramu- 
losus suffruticulosusve aut uniformis, matrici adnatus. 
It has been remarked already that Cladonia exhibits, within the circle 
of variations of a single species, what is now, so to say, Beomyces, and 
what is now Biatora; the disappearance of the podetium explaining the 
latter case, and the to this superadded prolongation of the apothecium 
downwards into a stipe, the former. But if Cladonia may thus fairly be 
taken to include, from the point of view of the fruit, both the other 
genera, and the tribe itself even, as Fries understood it, with scarcely an 
exception, disappear, from the same stand-point, asit does with Wallroth, 
in a single genus,! we may leave further argument to those who deny or 
disregard the affinities in question, and assume here the sufficiency of 
Fries’s demonstration of his Lecideacet. 
With not a little of the aspect, in some species (as B. imbricatus, 
Hook.) of an epiphylline Cladonia, and in others (as B. roseus) of such 
forms as Cladonia mitrula, and comparable again (as in B. byssoides) 
with Stereocaulon (to which Scherer once referred the species last-named, 
as Eschweiler the whole genus) Bcomyces is perhaps nearer to Biatora ; 
and with the exception of B. roseus, was united with it by Fries. Nor 
does it seem to be certain that the misus to develope vertically, so char- 
acteristical of the preceding family, and exhibited in Beomyces by the 
frequent extension of the hypothecium downwards into a stalk or stipe, is 
not properly predicable (as by Fries S. 0. V. p. 247) of the whole tribe, 
and therefore also of Biatora and Lecidea. The often elevated fruit of 
1 Patellaria, Wally. Fl. Crypt, Germ. exc. excip., the sections of which, refer- 
able here, differ in fact only, as the author says, ‘blastematis ratione, nec tamen 
cymatiorum natura,’ (1. c. 1, p. 348). 
