Oct., 1920 
The Queensland Naturalist, 
105 
AN INTERESTING COPEPOD. 
By W. R. Colledge. 
Our excursion to Goodna (3/6/20) yielded to the pond- 
hunters some fine specimens of Diaptomus. They are easily 
recognised by their antenmne, borne at right angles to, and 
sometimes quite as long as, the total length of the body. 
These organs, outstretched, balance the insect gracefully in 
the water. It moves steadily by means of its fan-shaped 
tail, edged with fine feathery setae ; but, more often, by a 
sudden contraction of the powerful muscles of the anteniije. 
Male Diaptomus. Female Diaptomns with spermatophore. 
Magnified 10 diameters. 
it slioots through the water as if propelled from a catapult. 
A brilliant eye of ruby colour gleams in the head. The pair 
of antennae are symmetrical in the female, but in the male 
one joint towards the extremity of the left is hinged, and 
the preceding joints much thickened in some species. 
During the breeding season the female carries a sac of 
eggs attached to the lower part of the abdomen. These are 
partly held in position by the fifth pair of feet, which are 
specially suited for that purpose. 
The male at this time provides what are technically 
known as ‘‘ spermatophores.’^ These are long sacs, each 
containing fluid, and a smaller sac inside filled with living 
sperms. Some brown granules lie in the bottom, and it is 
sealed with a plug of sticky mucus. When he approaches 
