MONOGRAPH OF THE LABOULBENI ACE/E. 



305 



widely distributed, is apparently a rare one, and abundant material is needed for its further 

 study. The hosts on which it occurs were taken under stones and in moss at the borders of 

 ponds. * 



Corethromyces setigerus Thaxtcr. Plate IX, fig. 6. 



Proc Am. Acad. Arts aud Sci. Vol. XXVIII, p. 181. 



Perithecium becoming tinged with brown, slightly inflated and tapering to the blunt apex ; 

 stalk-cell hyaline, long. Appendages arising from the distal and sub-distal cells of the recep- 

 tacle, consisting of two or three rounded basal cells, which bear numerous long, straight, cylin- 

 drical, septate, deep brown branches, some of them once branched, the whole curved slightly 

 outward and forming a crest-like structure. Basal cell of receptacle hyaline, the rest, including 

 the two appendage-bearing cells, strongly blackened externally. Perithecia, 110 x 35 fi. Spores 

 (measured in perithecium), 30 x 4 fi. Total length of appendages, 200 yu. or more. Two basal 

 cells of receptacle, 35 x 15 /x. Total length from base to tip of perithecium, 200-220 



On thorax of Lathrobium nitidulum Lee, Massachusetts ; on L. tenue Lee, Michigan. 



This species is closely allied to tlie preceding, yet seems sufficiently well marked to keep dis- 

 tinct. Its appendages are quite characteristic, recalling those of Laboulbenia cristata. The 

 main axes seem almost obsolete, being reduced to several rounded cells, which form a group, 

 from which arise the long, rigid, brown branches. The stalk-cells and lower basal cells of the 

 perithecium are much larger than in C. jacobimis, as is the perithecium itself. The material 

 examined was all obtained from specimens in the Museum at Cambridge, and is not in very good 

 condition. 



RHADINOMYCES Thaxter. Plate IX, figs. 7-15. 



Proc. Am. Acad. Arts and Sci. VoL XXVIII, p. 179. 



Receptacle consisting of two superposed cells, from the upper of which arise one to several 

 stalked perithecia and a main appendage ; the appendage consisting of three superposed cells, 

 the upper bearing terminally a series of simple sterile branches, the two lower producing from 

 their distal ends short antheridial branches or long sterile branches or both. Antheridial cells 

 flask-shaped, superposed in short series. Perithecia borne on a single stalk cell followed by four 

 basal cells ; its wall-cells four in each series. Spores once-septate. Trichogyne filamentous, 

 simple or branched. Ascogenic cells, four. 



In some instances the sub-basal cell of the receptacle may produce one or more antheridial 

 branchlets directly, in addition to those on the main appendage. The antheridial cells are some- 

 times single, more often superposed in threes, the upper one being free and terminal. A few 

 specimens have been observed in which the antheridial branchlets, instead of being borne 

 directly from the primary appendage, as in fig. 12, arise from some of its ordinarily sterile 

 branches. 



The ascogenic cells are readily made out in the paler species, and at maturity four may be 

 usually distinguished ; but this number does not seem to be constant even in the same species. 

 In a few instances a peculiar spine, present also in other genera, has been observed near 



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