APUS. 
29 
and go on gradually increasing, till, at the end of three 
weeks, they have reached the size of one inch in length. 
The process of moulting, or changing their skin, takes 
place about twenty times in the space of between two and 
three months, at which time they seem to have attained 
their full size. Schoeffer says, he never witnessed the pro- 
cess of moulting so as to be able to describe the mechanism, 
but it no doubt is the same as will be more fully described 
hereafter, when treating of the Daphnise. 
Schoeffer performed several experiments upon the Apus 
to ascertain whether it possessed the faculty of repro- 
ducing mutilated members. He found it had not, and 
that after moulting, the truncated members remained 
shorn of their fair proportions. It appeared, however, 
that the excision of one or two of its feet, or part of its 
rami, produced no bad consequences to the health of the 
individual so treated. 
This family contains only one British genus — Apus . 
Genus Apus.* 
Attovq, Frisch, 1732. 
Apus, Schaeffer, Latreille, Bose, & c. 
Monoculus, Linnaeus, Fabricius. 
Binoculus, Geoffroy, Leach , Diet. Sc. Nat., xiv, 538. 
Limulus, Muller , Lamarck. 
Triopes, Schrank. 
Character . — As this family at present contains only 
one genus, the characters given to it will be sufficient for 
the genus also. 
* A, privitive ; and ttovq, a foot. 
