THORACIC APPENDAGES. 139 



podites and endopodites, and aid in passing food to 

 the mouth. 



The thoracic appendages can be more easily removed, and 

 their relations determined, if the hranchiostegite he first cut 

 away. 



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

 as a type of the series. 



i. The protopodite consists of two segments, of which 

 the first, or coxopodite, is short and broad, 

 and bears a large gill and a tuft of long fine 

 hairs, the ' coxopoditic setse.' The second 

 segment, or basipodite, is much smaller, and 

 bears the endopodite. 



ii. The endopodite consists of five segments, named 

 as follows, beginning at the proximal end: — 

 iscMopodite, meropodite, carpopodite, propodite, 

 and dactylopodite. Of these the meropodite 

 and the propodite are the longest, and the 

 dactylopodite is clawlike. 



XIII. This, the last thoracic leg, differs from XII. in 

 having no gill. In the male the coxopodite is 

 perforated at its inner angle by the genital pore. 



XI. This resembles XII,, but the propodite is pro- 

 longed distally so as to form with the dactylo- 

 podite, a chele or pair of pincers. The inner 

 angle of the coxopodite is perforated by the 

 genital pore in the female. 



X. This is like XI., but has no genital pore. 



IX. This is similar to X., but much larger and 

 stouter, the terminal chele being especially large 

 and powerful. The basipodite and ischiopodite 

 are firmly fused together, as happens occasionally 

 in other limbs of the series. 



VIII. The third maxillipede is directed forwards under 

 the five appendages in front of it. 



