DAPHNIAD^. 75 



smaller than the three succeeding pairs, and is the most 

 simple of construction. It is situated immediately be- 

 hind the mouth, being inserted into the body of the 

 animal by the basal joint, which is broad and somewhat 

 fleshy. Attached to it is another joint of a triangular 

 shape, and haviug on its outer edge three small projec- 

 tions, each furnished with four or five long and strong 

 setae (analogous to the branchial plate of the succeeding 

 pairs). At the extremity of this joint is another very 

 small one, which is also furnished with one or two long 

 setae. All these setae are jointed at about the middle of 

 their length, and are not plumose. 



The second pair (t. VIII, f. f) is larger than the first, 

 and is inserted into the body a little behind it. It con- 

 sists of four articulations ; the basal broad, the second 

 somewhat quadrilateral and flatter, with three projections 

 at one extremity, the two internal sending ofi' each one 

 long plumose seta, and the external sending off three, 

 equally plumose. On each side of this second joint there 

 is situate another, one slightly quadrilateral, and sending 

 off from its external edge fifteen long setae, all jointed, 

 the external being much the longest and finely plumose ; 

 the other narrower and oblong, and furnished at its 

 extremity with two plumose setae. The larger of these 

 two may be considered as a branchial plate. In the 

 third pair (t. VIII, f. g), the second joint is longer than 

 that of the preceding pair, and sends off" from its inferior 

 extremity two short simple setae. The branchial plate is 

 attached to its external face, is larger and longer than in 

 the preceding pair, and has numerous filaments on its 

 free edge (Straus reckons seventy-six). The fourth arti- 

 culation is laiger than that of the preceding pair, is broad 

 and nearly quadrilateral, and sends ofl" six long plumose 

 setae, four from the inferior edge, and two from its 

 internal side. The fourth pair (t. VIII, f. h) is similar to 

 the third. The branchial plate has fewer filaments 

 (Straus reckoning only sixty-five), and the fourth articula- 

 tion is more oblong, and larger. The fifth pair (t. VIII, f. i) 



