266 



MONOGRAPH OF THE LABOULBENIACEiE. 



any reasonable doubt the vexed question as to the presence of sexuality in the higher fungi. The 

 immediate relation of the present to other genera, with the exception of Dimeromyces, is not 

 clear ; yet it seems probable that among described forms the species of Dichomyces and Pey- 

 ritschiella approach it more nearly than any others. In both of these instances the same ten- 

 dency towards a bilateral development is combined with a close correspondence in the sexual 

 organs. 



Dimorphomyces denticdlatus Thaxter. Plate V, figs. 11-16. 



Proc. Am. Acad. Arts and Sci., Vol. XXVIII, p. 157. 



Male individual. Receptacle of four superposed cells, the distal one tapering upward, and 

 terminated by a more or less distinctly marked, usually slightly blackish, knob. Antheridium 

 arising from the sub-basal cell and partly united to the sub-terminal cell of the receptacle ; ex- 

 ternally nearly straight, bulging internally ; its main body about as long as the usually straight 

 terminal neck, the base of which is distinctly inflated to form the cavity into which are dis- 

 charged the antherozoids. Total length to tip of receptacle, 40/a ; to tip of antheridium, 50- 

 55yti. Greatest width, 14/x. 



Female individual. Sterile portion of the receptacle consisting of a large sub-terminal and 

 much smaller nearly spherical terminal cell, the main portion consisting of two superposed 

 cells forming a more or less three-sided body, the perithecia and sterile appendages arising in 

 the manner characteristic of the genus. Perithecia slightly inflated, rather abruptly contracted 

 to form the stalk portion ; the tip oblique ; one of the lip-cells projecting as a short but distinct 

 tooth-like prominence ; while just below this prominence a conspicuous tooth-like outgrowth 

 arises from one of the anterior sub-terminal wall-cells, and extends obliquely upward and out- 

 ward more than half its length beyond the tip of the perithecium. The stalk of the perithe- 

 cium is usually strongly curved, so that the latter is bent backward beyond the terminal 

 portion of the receptacle. Sterile appendages simple, septate, tapering slightly, usually bent 

 away from the perithecia. Spores 22-25 x 3/x. Perithecia 65-70 x 15/x. Appendages about 

 110/4. Receptacle about 40/^ long. 



On Falagria dissecta Br., Waverly, Mass., and Kittery Point, Maine. 



Better and more abundant material of this species has made necessary important changes 

 in the original diagnosis above cited. The species is a rare one, occurring on the abdomen of 

 its host close to the edges of the last abdominal rings on the upper or under sides, and may be 

 seen projecting beyond their margin in a position indicated in fig. 2. They occur always in 

 pairs, comprising the two sexes ; and numerous pairs are not infrequently found crowded together 

 and producing a little tuft which may be seen without great difficulty under a hand lens. The 

 anterior face is usually turned towards the substratum, and the divergence of the appendages 

 and perithecia gives the plant a characteristic habit, indicated in fig. 11, and makes it almost 

 impossible to obtain a view which is either wholly posterior or wholly anterior. The species 

 seems a very constant one, varying but slightly in size, and usually producing only two peri- 

 thecia. The host, Falagria, may be obtained in great abundance from almost any decaying 

 vegetable matter in fields, and is most readily captured by shaking such material over a white 

 cloth. It is the smallest host known to be infested by any of the Baboulbeniacea?. 



