164 C. B. WILLIAMS. 



irrigation or flooding, the lower system, usually about four feet below the other, 

 is the drainage canal. In only one part of the coast under consideration is there 

 any rise in the ground and this is just on the western side of the Essequibo River, 

 where there are a few low sand ridges. The coast of Dernerara proper (which extends 

 from the Berbice to the Essequibo Rivers) (see map, fig. 1) is divided by the 

 Dernerara River into the East Coast and the West Coast ; the Corentyn Coast, east 

 of the Berbice River was not visited. 



The following is the average for 32 years of the rainfall at the Botanic Gardens, 

 Georgetown, Dernerara : 



Jan. Feb. Mar. April May June July Aug. Sept. Oct. Nov. Dec. Total 

 8-4 6-8 7-5 7-3 11-5 12-1 10-6 6-3 3-1 2-4 5-3 1.1-5 91'3 



During these 32 years the total annual rainfall has varied from 59 to 135 inches. 



It will be seen that there are two dry seasons, one during February, March and 

 April, and a second from about the middle of August to the middle of November. 



The coast land is almost entirely under cultivation, that nearest the sea, immediately 

 behind the sea defences, being largely used for rice-growing (the area under which 

 is increasing every year), and very wet pastures for cattle, sheep and goats. Behind 

 this, usually from about two miles to about eight miles from the sea, are the chief 

 sugar fields. These stretch further inland up the river margins. A small area 

 near Georgetown, once in sugar, is now used by market-gardeners. There is very 

 little uncultivated land. Most of the wild plants are grasses and sedges, which are 

 found in the pastures along the canal banks and roadsides, and to a lesser extent 

 among the canes. 



The British Guiana Froghopper. 



The froghopper found attacking the sugar-cane along this coast is Tomaspis 

 flavihtera, Urich. It has not yet done any serious damage, but is viewed with 

 suspicion by the planters after what has been experienced in Trinidad. 



They were first discovered by Mr. J. J. Quelch at Plantation Melville, East Coast, 

 about 1909. In 1911 Mr. H. W. B. Moore reported that they were common only 

 at Melville (Report for 1911, p. 20). They were found chiefly on grass and were 

 preyed on largely by Attid spiders. In 1912 there was a long drought and the frog- 

 hoppers almost disappeared, but in 1913 they were again seen on several estates, 

 particularly Plantation Cane Grove, East Coast, and Plantation Ogle, East Coast. 

 They were chiefly on the grass and less on the cane. (Moore, Report for 1913, p. 1 5.) 



In 1914 Urich gave a short general account of froghoppers in the Journal of 

 the Board of Agriculture of British Guiana for the use of the local planters. 

 T. flavihtera is mentioned as occurring in British Guiana, but is not thought to be 

 very serious. A list of the chief enemies of T. saccharina in Trinidad is given and 

 it is suggested that most of them probably occur in British Guiana. 



In 1914 " From June to August there was a fairly sharp attack. On some fields 



of Cane Grove over 50 nymphs of various ages were counted attached to the 



rootlets of some stools. Froghoppers were also observed at Plantation Ogle, but 

 the attack was not of much consequence. Numbers of nymphs were destroyed 

 here by pounding and crushing " (Moore, Report for 1914, p. 15). In June of the 



