198 
ST. HELENA. 
cases the prey is secured, but sometimes it escapes, leaving the dis- 
appointed enemy exhausted with his warlike exertions. In a 
similar way it attacks S. merdaria. 
S. merdaria, Fabr. — Both this and the last species are the 
common Dung-flies of Europe; they are very abundant along the 
roads and in the fields at St. Helena. 
Fam. Geomyzidce. 
Drosophila, Fall. 
*D. repleta, Walk.— An extremely small Fly, very abundant near 
streams of water, and in wet marshy places. It is sometimes so 
plentiful in such localities as to produce a sensation of choking, when 
you inhale them in the act of breathing. It is general throughout 
the Island. 
Fam. IEppoloscida:. 
Hippobosca, Linn. 
. H - equina ’ Linn.— Known as the Horse-fly. This insect is rare 
m the Island. Mr. Walker says “ Perhaps II. variegata is a 
variety of this species.” 
Order Hemiptera. 
Hie Bugs are not largely represented ; one very characteristic 
species is, however, as well known in St. Helena as in most parts of 
the woild. Aphides are very abundant, many of them occurring 
upon the native vegetation, and therefore well worthy of the atten- 
tion of future collectors. 
Eight species of this Order have been examined by Mr. Walker ; 
two are described as natives, and it is probable that two others may 
also prove to be so. 
Fam. Pentatomida. 
Ehaphigaster, De Lap. 
R. prasinus. A large green, garden Bug, whose disagreeable 
odour soon denotes its proximity. It is found in most gardens both 
on the high and low lands. 
