the basal parts of each, see which are alike and then draw one of 

 each kind or set, keeping all of the small ones in water in watch 

 glasses. 



I. ABDOMINAL APPENDAGES OR SWIMMERETS. 



Composed of a two joined protopodite, and an exopodite and an 

 endopodite each with many joints ; found on all but the first and 

 sixth somites (and the second also in the male) where the appen- 

 dages are more or less modified. 



II. THORACIC APPENDAGES. 



There are five pairs of ambulatory, and three pairs of masticatory 

 appendages (the maxillipedes). 



a. The posterior pairs of ambulatory appendages have the fol- 

 lowing seven joints: (i) Coxopodite, the short and very thick basal 

 joint. (2) Basipodite, a very small and conical joint. (3) Ischio- 

 poditc, cylindrical and with a groove around it. 14) Meropodite, 

 very much longer than the last. (5) Carpopodite, about half as long 

 as the last. (6) Propoditc, slender and long. (7) Dactylopodite, 

 the short, pointed terminal piece. (Of these (i) and (2) probably 

 correspond to the protopodite of the abdominal appendages, and the 

 other five to the endopodite, as may be seen by comparing all of the 

 other appendages with the third maxilliped. 



b. The next pair of appendages have in addition a branch-id and 

 epipodite upon the coxopodite and extending up into the branchial 

 chamber. 



c. The third and fourth appendages (counting forward) differ in 

 having the propodite produced opposite the dactylopodite to form 

 a pair of forceps. 



d. In the large anterior pair of ambulatory appendages, the 

 chelae, the forceps is greatly enlarged and the basipodite and 

 ischiopodite are united into one piece. 



e. The third or posterior maxilliped should be carefully studied. 

 Note: d) The large basal part, protopodite, bears a long five 

 jointed endopodite and a slender many jointed external exopodite, 

 besides a curved lamella, epipodite, lying in the branchial chamber 

 and bearing a branchia. (2) The protopodites and endopodites 

 make up together a seven jointed organ like the ambulatory ap- 

 pendages. 



f. The second maxilliped differs from the last mentioned, 

 chiefly in the size of the endopodite. 



g. In the first maxilliped the endopodite is short and flat, the 

 protopodite two jointed and foliaceous, the epipodite has no gill. 



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