8 ILLINOIS BIOLOGICAL MONOGRAPHS [174 



Coverden on the bank of the Demerara about 20 mi. from the sea gives 

 a few isolated sand hills covered with the original forest growth of great 

 diversification which differs essentially from that found elsewhere. 



Tumatumari on the Potaro River about 150 mi. inland is in the foot- 

 hills surrounded by tropical jungle which may be traversed for many miles 

 on foot by way of cut trails. 



Kartabo, the temporary location of Dr. Beebe's laboratory, on the 

 point formed by the junction of the Mazaruni and the Cayuni rivers, and 

 only a few miles from the junction of the Essequibo is also in primitive 

 jungle. All of these localities, except that of Georgetown, are without 

 apparent influence of man on the flora, and its wilderness is evidenced by the 

 sight at any moment of tapirs, peccaries, monkeys, deer, ant eaters, or 

 possibly a boa constrictor. 



The itinerary included also a few days collecting in Trinidad confined 

 chiefly to the immediate vicinity of the Port of Spain, St. Augustine, 

 Cumuto and The Long Stretch. 



Practically no collections or records have previously been made of the 

 parasitic fungi of British Guiana. Though my collections can be regarded 

 only as a mere sampling they reveal a very rich fungous flora, especially 

 rich in the Dothideales, Sooty Molds, Microthyriaceae and with a con- 

 siderable abundance of rusts. The smuts are very scarce and the imperfect 

 fungi, Phyllosticta, Cercospora, etc., are apparently less common than in 

 the temperate region. 



The summer's collection consisted of approximately a thousandnumbers, 

 only certain families of which are reported in this paper; the genus Meliola, 

 the Microthyriaceae, most of the Hemisphaeriaceae, the Trichopeltaceae 

 being reserved. The slides, notes, original drawings and specimens on which 

 these studies are based are deposited in the herbarium of the University of 

 Illinois and duplicate specimens in the New York Botanical Garden. The 

 photographs reproduced in the plates were made by A. G. Eldredge; the 

 line drawings by L. R. Tehon. 



The arrangement and classification of the Dothideales followed in this 

 article is adapted from that of Theissen and Sydow' and, in so far as con- 

 cerns the genera herein reported, is shown in the table of contents. 



The following is a list of the field numbers with places and dates of 

 collection. 



Trinidad Date 



Nos. 1 to 8 Port of Spain June 28 



British Guiana 

 Nos. 9 -18 Georgetown July 2 



•Theissen, F. and Sydow, H., Die Dothideales. .^nn. Myc, 13:149-746, 1915, and 

 Synoptische Tafeln., Ann. Myc, 15:389, 1917. 



