Hab. Hermite Island, Cape Horn; on leaves of Viola tridentata.
Amphigena, punctiformis. Mycelium vadle obscurum, e filamentis paucis brevibus parec ramosis. Perithecia depressa, atro-fusca, e cellulis radiautibus elongatis subregularibus formata; margine tenui lacerato membranaceo pellucido.
Neither have I been able to detect fructification in this plant, but the genus is I believe certain.
Plate CLXIV. Fig. IV.—1, Viola attacked with Fungus of the natural size; 2, leaf of ditto and Fungus; 3, perithecium; 4, portion of edge of ditto:—highly magnified.
3. Asterina Darwinii, Berk.; epiphylla, maculis parvis orbicularibus e fibrillis radiantibus articulatis inarticulatisque, peritheciis irregularibus demum depressis centralibus margine laciniato. (Tab. CLXIV. Fig. II.)
Hab. Cape Tres Montes; on Azara lanceolata; C. Darwin, Esq.
Maculæ epiphyllæ, orbiculares, ½-1 lin. latæ, e fibrillis radiautibus reticulatisque, partim e margine perithecii, partim e superficie inferiore enatæ, breviter articulatæ, aut omnino simplices. Perithecia primum irregularia, subelevata, demum depressa, margine laciniato laciniis denticulatis. Asci ut in reliquis speciebus globosi; sporidia oblonga, biloculata.
Apparently different from A. Azara, Lév., in its perithecia, which are not depressed in the centre, as in that species. Unfortunately I have no opportunity of comparing them. The perithecium, both here and in Asterina microscopica, splits from the centre in a radiating manner when slightly pressed.
Plate CLXIV. Fig. II. — 1, Asterina Darwinii, Berk., on leaves of Azara lanceolata, of the natural size; 2, perithecia and mycelium; a, cuticle of matrix; b, incipient perithecium; c, curious processes given off from threads of mycelium; 3, fibres of mycelium; 4, portion of border of perithecium; 5, processes on threads of mycelium; 6, asci; 7, sporidia:—all very highly magnified.
19. EUROTIUM, Lk.
1. Eurotium herbariorum, Lk., Obs. vol. i. p. 29. f. 44.
Hab. On biscuit on board the 'Erebus', Jan. 3rd, 1841.
The sporangia in the specimens before me, which are very scanty, are almost destitute of flocci, but accompanied by an abundant tawny mycelium, thus confirming the opinion of Fries and Corda, that Eurotium epixylou is not really a distinct species. I cannot, however, think with Corda that it has the slightest affinity with Physarum. The morphosis has not at present been traced, and till this is done it appears better to let it remain where Fries has placed it, in the neighbourhood of Mucor.
The peridium is lined with a stratum of gelatinous cells, which vanish in a great measure as the plant approaches maturity. The flocci in Kze. and Schm., n. 83, are rough and dark, but I find great variation both of surface and colour.
LV. ALGÆ, L.
1. D'URVILLÆA, Bory.
1. D'Urvillæa utilis, Bory, in Duperrey Voy. Bot. p. 65. t. 1 et 2. f. 2. Fl. Antarct. Pt. 1. p. 167. Laminaria cæpæstipes, Montague in Voy. D'Orbigny, Bot. Crypt. p. 11. t. 2.
