34 THAXTER. 



antheridia, which often occur in fours; and the a])rupt and peculiar 

 distal modification of its perithecium ; which is, however, faintly 

 suggested by the bent tip of R. Stenotarsi. Were it not that the mate- 

 rial of both is abundant and in perfect condition, and the individuals 

 clearly distinguished in all cases, I should hesitate to separate them, 

 and in any case it may eventually prove more desirable to separate 

 the present form as a var. latior of the preceding. 



Rickia introversa nov. sp. 



Straight, short and stout, as\Tnmetrical. Receptacle triseriate, 

 the cell-numbers somewhat variable; the foot and basal cell large, 

 the latter more or less completely and deeply involved by a brownish 

 black suffusion; its apex slightly intruded between the cells above it: 

 anterior series consisting of about sixteen cells and extending to the 

 tip of the perithecium, which is bent abruptly over its broad, blunt 

 termination; the subterminal cell and the one next below, extending 

 higher than the small terminal one, which lies against the concave side 

 of the perithecial tip; all the cells, except four or five of the flattened 

 terminal ones, and usually also the basal, being sharply pointed out- 

 ward; owing to the separation, distally, of a narrow cell, sharply 

 pointed inward, which, in the lower members, may be nearly as broad 

 as the cells from which they are separated, and which bear externally 

 antheridia or appendages: posterior series similar in general to the 

 anterior, consisting of six or seven stouter cells and ending in the lower 

 of the two cells which form the base of the primary appendage; all, 

 usually including the lowest, bearing antheridia or appendages later- 

 ally, not marginally, as in the anterior series; so that, when they lie 

 at the right, their origins are not visible: median series consisting of 

 four or usually five cells, its much larger basal cell not at all or but 

 slightly intruded below. Appendages closely appressed, distally 

 hyaline, and not clearly distinguishable, except their contrasting 

 blackish brown bases, the suffusion extending some distance above the 

 indistinguishable basal septum, and also involving more or less dis- 

 tinctly the cell which bears them. Primary appendage of the normal 

 type, unlike the secondary; its base not clearly differentiated from 

 the cells below it. Antheridia very large, scanty, appressed, or over- 

 lapping the receptacle; the necks long and stout, not abruptly dis- 

 tinguished. Anterior margin of the perithecium hyaline, united to 

 the receptacle as far as the tip, which is bent abruptly over the rounded 



