Rev. W. A. Leighton on new British Lichens. 403 
somewhat the appearance of the thallus of Lecidea citrinella, Ach., 
or even of the undeveloped apothecia of a Lecanora; but the mi- 
croscope and dissection show such appearances to be mere resem- 
blances. 
Thelocarpon Laureri was first discovered by Flotow, in 1824, 
in marshy places in the county of Glatz, Germany; and his 
specimens appear to have lain in his herbarium undetermined 
until 1846, when M. Laurer again found the lichen on turf 
fences at Greifswald, and then drew M. Flotow’s attention to it. 
Flotow then described it, under the name of Spheropsis, in the 
‘Botanische Zeitung,’ 1847, p. 65, with this character :— 
* Spheropsis, Fw. (Verrucariese, Porinese).— Apothecium verruci- 
forme, ostiolatum, e thallo formatum, includeus nucleum soli- 
tarium gelatinosum achromaticum. Perithecium proprium nul- 
lum. Asci basilares ventricoso-fusiformes ; sporas minutas ovales 
numerosissimas hyalinas foventes. 
“ Spheropsis Laureri, Fw.—Sph. hypothallo inconspicuo, crusta 
granuloso-verrucosa, flavo-viridi; verrucis acolytis plus minus 
confertis, fertilibus ostiolo impresso nigricante. Habitat ad 
aggeres turfosos (Greifswald, Laurer, 1846) et in ericetis hu- 
midis (Grafschaft, Glatz, 1824). Fw. herb. 1824, n. 285.” 
Soon after, however, discovering that the name Spheropsis 
had been already appropriated to a genus of Fungi, M. Flotow, 
in his letters (in 1848) to various botanical correspondents, 
changed it to Thelomphale. Dr. William Nylander, apparently 
without knowing of Flotow’s change of name, described an- 
other closely allied species from Algeria (7. albidum, Nyl.), mm 
1854, altermg the generic name to Thelocarpon, which he has 
retained in all his subsequent works. Korber, in the 4th part 
of his ‘ Parerga Lichenologica,’ published in 1863, relates the 
circumstances of Flotow’s early change of the name to Thelom- 
phale, which he himself adopts. Nevertheless Nylander’s name 
Thelocarpon has priority of publication, and must, of course, be 
adopted. 
Only three species of the genus are known: T. Laureri, Fw., 
in Germany and England; 7. albidum, Nyl., with white thallus 
and uniseptate sporidia, in Algeria; and 7. coccophorum, Mntg., 
in Chili (apparently a doubtful species). 
Dr. Korber has compared our plant with his authentic speci- 
men, and finds them identical. Dr. F. Arnold, of Hichstatt, in- 
forms me that the German habitat is now destroyed. 
Puate IX. fig. 1. Plant, magnified 20 times. 
2. Vertical section of apothecium. 
fig. 3. Asci and paraphyses in stellate form. 
4. Ascus and paraphyses. 
5. Sporidia, magnified 1200 times linear. 
26* 
