162 PROCEEDINGS OF THE AMERICAN ACADEMY 



120-140 X 26 fjL. Length of appendage to tip of antheridium 110- 

 150 fi. Total length to tip of perithecium 280-335 /x. 



On abdomen of Bledius armatus Er., Utah. 



Distinguished from G. Bledii by its brown color, the greater elon- 

 gation of the basal cells of the perithecium, and the relatively small 

 antheridium, which in G. Bledii is external and comprises about five 

 sixths of the sub-basal cell. The two specimens examined have each 

 a single perithecium, and but one appendage, the x.\\) of which is 

 somewhat broken. A number of young specimens apparently belong- 

 ing to this species, and occurring on B. jacobinus Lee, have the ter- 

 minal portion of the appendage unbranched and consisting of a short 

 series of superposed cells. 



IDIOMYCES, nov. gen. 



Receptacle short ; flattened, terminated on one side by a series of 

 superposed cells bearing externally a vertical row of closely set appen- 

 dages, on the opposite side by one or more stalked perithecia at the 

 base of which on one side arises a second transverse series of simi- 

 lar appendages. Perithecia straight, symmetrical, borne on a stalk 

 composed of a single basal and several terminal cells. Appendages 

 consisting of a series of antheridial cells, their projecting necks forming 

 a comb-like appendage which may be terminated by short branches. 

 Spores as in other genera. 



The appendages of this curious genus recall those of Stigmatomyces, 

 which is perhaps its nearest ally. The arrangement of these appen- 

 dages in two series, one upon a differentiated and the other upon an 

 undifferentiated base, is remarkable and peculiar to this genus which 

 is very probably identical with that referred to by Peyritsch * as 

 occurring on Deleaster in Austria. 



Idiomtces Petritschii, nov. sp. 



More or less tinged with yellowish or reddish brown. Receptacle 

 consisting of two superposed basal cells, surmounted by two cells ; the 

 outer, having a very thick external wall which forms a distinct prom- 

 inence distally, is succeeded by a row of about five or six superposed, 

 more or less flattened cells, extending beyond the base of the perithe- 

 cium, which bear externally a vertical series of closely set appendages : 

 the inner is succeeded by a single rounded cell followed by several 

 small cells which give rise to a transverse series of about six appen- 



* Sitz. d. Wien. Akad., 1875, LXXII. Abth. 3. 



