ABDOMINAL APPEND AG-ES 131 



XV. In the female this resembles XVIII., but is Hable 

 to reduction, and may be absent. 



In the male it is normally turned forwards 

 and is specially modified for transferring the 

 spermatozoa to the female. The protopodite 

 and exopodite resemble those of XVIII., but the 

 large proximal joint of the endopodite is pro- 

 duced distally on its inner side into a short 

 plate, rolled longitudinally upon itself to form 

 an imperfect tube : the remainder of the endo- 

 podite is a small jointed rod as in XVIII. 



XIV. In the female this is reduced or absent. 



In the male it is modified for the same pur- 

 pose as XV. It is an unjointed rod, the distal 

 portion of -which is flattened and rolled upon 

 itself to form an imperfect tube. It is probably 

 formed of the protopodite and endopodite fused 

 together. 



The thoracic appendages, of which there are eight pairs, 

 fall readily into two groups : a posterior group of 

 five pairs of large appendages, XIII. to IX., used for 

 walking and prehension, and devoid of exopodites ; 

 and an anterior group of three pairs of maxillipedes 

 or foot-jaws, VIII. to VI., which possess both exopo- 

 dites and endopodites, and aid in passing food to the 

 mouth. 



XII. The last but one of the thoracic legs may be 



taken as a type of the series. 



i. The protopodite consists of two joints, of which 



the first, or coxopodite, is short and broad, 



and bears a large gill and a tuft of long fine 



hairs, the ' coxopoditic sets.' The second 



joint or basipodite is much smaller, and bears 



the endopodite. 



ii. The endopodite consists of five joints named as 



follows, beginning at the proximal end : — 



ischiopodite, meropodite, carpopodite, pro- 



K 2 



