rance when
fresh, but gives the spore-mass yellow; only in the stipe does he find
another tint, nut-brown-purple. The figure, 145 in the _Monograph_ now
before us portrays, except in color, our _C. tenella_ exactly. Dr. Rex,
_Bot. Gaz._, XIX., 398, compares the present species with _C.
minutissima_, and _C. tenella_ with _C. dictydioides_; which is correct
for the American presentation of the species named. _C. dictydioides_ is
certainly our presentation of _C. intricata_, a geographic species at
the least; but if _C. microcarpa_ is purple we have of it no
representation; our forms under that name are closely related to _C.
tenella_, a yellow-spored species, and might perhaps be there referred;
have, however, somewhat larger spores.

12. CRIBRARIA VIOLACEA _Rex._

PLATE XVII., Fig. 8.

1891. _Cribraria violacea_ Rex, _Proc. Phil. Acad._, p. 393.

Sporangia scattered or gregarious, very small, .2 mm. in diameter,
violet tinted, erect, stipitate short, about one-half the total height,
concolorous, slender, tapering upward; calyculus crateriform,
persistent, or marked with minute plasmodic granules; the net
rudimentary or poorly developed, the meshes large, irregular, the
nodules also large triangular, violaceous; spores pale violet in mass,
by transmitted light reddish, 7-8 mu, minutely warted.

A very minute but well-marked species discovered by Dr. Rex in
Wissahickon Park, near Philadelphia, otherwise very rare. Lister,
however, reports it from England. In minuteness to be compared with _C.
minutissima_, from which its color instantly distinguishes it. Dr. Rex
reports the plasmodium as "violet black." All our specimens are on very
rotten wood, basswood, _Tilia americana_.

Pennsylvania, Illinois, Iowa.

13. CRIBRARIA PURPUREA _Schrad._

1797. _Cribraria purpurea_ Schrad., _Nov. Gen. Pl._, p. 8.

Sporangia gregarious, large, 1 mm. in diameter, dark purple, erect,
stipitate, depressed-globose; stipe concolorous, furrowed, about twice
the diameter of the sporangium in length, with a distinct hypothallus;
calyculus persistent, less than half the sporangium, obscurely ribbed,
marked by concentric plications, the margin toothed; the net poorly
differentiated, the meshes irregular in form and size, as are also the
flat, unthickened nodes, the threads pale, free ends short and not
numerous; spore-mass purple; spores by transmitted light, pale or
colorless, 5-6 mu, smooth.

Rare. Found on rotten coniferous