Chapter IV: DICTYDIUM, Schrad. Sporangium simple, depressed-globose, stipitate,

cernuous; the wall regularly thickened on the inner surface by numerous convergent ribs, which extend from base to apex and are united by fine transverse fibers, thus forming a network of rectangular meshes; the basal portion of the membrane sometimes persists as a calyculus, the upper part disappears at maturity. Spores globose; purplish.

The ribs run from base to apex like the meridians on a globe; they are simple, or here and there they separate into two divergent branches, which sometimes again converge into one; at the apex of the sporangium there is usually a small irregular net in which all the ribs terminate.

1. DICTYDIUM CERNUUM, Pers. Sporangium depressed-globose, umbilicate at the apex, stipitate, cernuous, purplish-brown in color; the calyculus granulose within, occupying from one-fourth to one-third of the sporangium, the ribs united by firm, persistent fibers. Stipe not very long, erect, tapering upward, bent at the apex, purplish-brown, the apex pale and pellucid, standing on a small hypothallus. Spores purplish-brown in mass, globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or three times longer than the diameter of the sporangium. This appears to be the species figured and described by Rostafinski and by Massee.

2. DICTYDIUM LONGIPES, Morg. n. sp. Sporangium large, depressed-globose, the apex umbilicate, stipitate, cernuous, dark purple in color; calyculus usually wholly wanting, the ribs united by weak fibers, which are easily torn asunder, allowing the ribs to curl up inwards. Stipe very long, flexuous, tapering upward, curved and twisted at the apex, dark purple in color, standing on a thin hypothallus. Spores in the mass dark purple, globose, even, 5-7 mic. in diameter. See Plate III, Fig. 12.

Growing on rotten wood, mosses, etc. Sporangium .5-.7 mm. in diameter, the stipe three to five times as long. This is a much larger species than the preceding; it has a uniform dark purple hue, the stipe is very long and much bent and twisted, the ribs of the sporangium are soon torn apart and rolled inward.

EXPLANATION OF PLATE III

Fig. 1.--Licea biforis, Morgan, n. sp.

Figs. 2, 3, 4.--Diagrammatic representation of the structure of Tubulina

Fig. 5.--Lycogala conicum, Pers., natural size

Fig. 6.--Lycogala exiguum, Morgan, n. sp., natural size

Fig. 7.--Lycogala epidendrum, Buxb., natural size

Fig. 8.--Lycogala flavofuscum, Ehr., natural size

Fig. 9.--Portion of tubule of Lycogala flavofuscum

Fig. 10.--Reticularia splendens, Morgan, n. sp., natural size

Fig. 11.--Cribraria cuprea, Morgan, n. sp.

Fig. 12.--Dictydium longipes, Morgan, n. sp.

VOL. XV. PLATE III.]

* * * * *

From the Journal of the Cincinnati Society of Natural History, April, 1893.

THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Second Paper.

(Read May 2, 1893.)

ORDER III. PERICHÆNACEÆ.

Sporangia sessile or plasmodiocarp; the wall a thin membrane, with a more or less thickened outer layer of minute brownish scales and granules. Capillitium of long and very slender tubules, proceeding from numerous points of the sporangial wall, loosely branched, forming no evident network, the surface minutely warted or spinulose. Spores globose, oval, or somewhat irregular, yellow.

The order is distinguished by the sessile sporangia, with thick brown walls, and the very slender threads of the capillitium, with irregular and indefinite markings.

TABLE OF GENERA OF PERICHÆNACEÆ.

1. PERICHÆNA. Sporangia more or less depressed, roundish or more commonly polygonal and irregular, dehiscent in a circumscissile manner.

2. OPHIOTHECA. Plasmodiocarp terete and more or less elongated, bent and flexuous, sometimes annular or reticulate, irregularly dehiscent.