264 ZOOBO.GNG 
The Copepoda are divided into two sub-orders: (i.) the 
Branchiura, which includes the two genera Argulus and Gyro- 
peltis; and (i1.) the Eucopepoda, which embraces the mass of 
the Copepods, both free-swimming and parasitic. 
(i.) The Branchiura are known as Carp-lice, Argulus 
being parasitic upon Carp and Sticklebacks. These animals 
differ considerably from the members of the Eucopepoda. In 
Fia. 157.—Argulus foliaceus, female, 
seen from the ventral side. After Jurine. 
1. Pointed rostrum. 
2. Antennules. 
3. Antennae. 
4, Hye. 
5. Sucker on anterior ramus of 2nd 
maxilla, 
Liver. 
Ovary. 
oN SD 
Eggs leaving the body. 
oe) 
. Posterior ramus of 2nd maxilla. 
Argulus the mouth is prolonged into a suctorial tube, within 
which lie concealed the serrated mandibles and_ styliform 
first maxillae: a modification of the mouth parts which is 
common amongst certain orders of Insects. In front of the 
mouth is a styliform weapon, which also lies in a sheath. The 
second pair of maxillae, the so-called maxillipedes, are modified 
to form organs of adhesion, the anterior ramus taking the form 
of a sucking disk, the posterior being hooked. Behind these 
are found four pairs of swimming legs, all of them, except the 
last, concealed by the body. The abdomen terminates in 
two caudal plates; the whole body is flattened dorso-ventrally. 
The male is more active than the female, and possesses copu- 
latory appendages on the last thoracic limbs; the eggs are not 
carried about in the usual Copepod fashion, but are deposited 
upon surrounding objects. 
