366 PROCEEDINGS OF THE AMERICAN ACADEMY. 



The only American form, R. minuta, thus far recorded on Acari, 

 has been described by Paoli ("Redia," Vol. VII, fasc. 2, 1911, repub- 

 lished in Malpighia, Vol. XXIV, 1912) from immature specimens 

 with undeveloped perith»ecia, a practice which it is surely most desir- 

 able to avoid in the systematic study of a group which presents such 

 great difficulties as do the Laboulbeniales. I have been fortunate, 

 however, in obtaining abundant material of this species, fully matured, 

 from the Amazon region, for which as well as for other hosts, I am 

 indebted to the kindness of Mr, W. H. Mann who has allowed me to 

 look over his collections made on the Leland Stanford Expedition 

 in 1911. I am further greatly indebted to the kindness of Messrs. 

 T. Fetch, Geo. Schwab and J. B. Rorer who have most generously 

 collected or caused to be collected for me numerous insects, in Ceylon, 

 Kamerun and Trinidad respectively, from among which a majority 

 of the following hosts were obtained. I am also indebted for two 

 species of Acari collected in Grenada to Mr, C. T. Brues and kindly 

 placed at my disposal; while lastly I am much indebted to Mr. 

 Nathan Banks for his determinations of the host-genera. 



In the following diagnoses I have assumed that the side bearing 

 the perithecium is "anterior." The spore measurements are for the 

 most part made within the perithecium. 



Rickia furcata nov. sp. 



Furcate, sometimes irregularly branched. Basal cell short and 

 rather stout, the receptacle above it dividing in two straight divergent 

 branches; an anterior, bearing a perithecium, and a posterior. An- 

 terior branch consisting of a series of usually eleven cells, the lower 

 superposed horizontally, the upper obliquely; all cutting off appen- 

 diculate cells externally; the series extending nearly to the apex of 

 the perithecium, to which it is united throughout its length; the 

 second cell of the series extending inward below the base of the latter, 

 the outline of which is symmetrically subfusiform, the inner lip-cell 

 protruding as a finger-like process. Fosterior branch indeterminate, 

 formed by a double series of cells which are more or less regularly 

 paired above the second cell of the outer row, the third cell bearing 

 the primary appendage on its narrow subtending and long cylindrical 

 basal cell; many, but not all of the cells above in both rows cutting off 

 distally and externally small cells which bear well-developed appressed 

 appendages or antheridia (?). Appendages subcylindrical, 8-16 X 

 2.5 ju. Ferithecium 30^0 X §-10 /x, including terminal projection 



