HIPPOBOSCA EQUINA. 313 
sometimes called spider fly^ from a fan- 
cied resemblance to a spider ; otiiers call 
it the horse leech, or horse fly ; but all 
these names are improper, because they 
make a confusion of terms. 
Lucy, How, mamma f for I have 
often seen brown flies, with beautiful 
green eyes, that sadly worried horses. 
Mother. Yes, Lucy ; and that affords 
an instance of the confusion, which call- 
ing the hippoboscse, horse flies, would 
occasion, since horse fly is the name 
commonly given to the tahanus, which 
in summer and autumn torment our 
cattle. 
Lucy. You did not give me any ac- 
count of the tabanus. 
Mother, No, I did not, because, though 
the fly is very common, the larva is uur 
known : the fly has a large proboscis, 
armed w^th a sharp lancet ; it sucks large 
quantities of blood, and gives great pain 
to the creature it attacks. 
Lucy, And why is it wrong to call 
tjie hippobosca a horse leech ? 
