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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



to one-half distance to the base of sinus. Respiratory area as in 

 figure 45, a. 



First antennae with anterior hook and a ventral spine, none at 

 base; flagellum with biramous tip, one branch secondarily branched; 

 second antennae with spine at base; third spine near midline. 



Suction cups with 12 to 14 segments in ribs supporting the rim 

 (fig. 45, h). Second maxillae stout, rounded papilla on posterior 

 ventral surface of third joint opposing claws of terminal joint on 

 male; basal plate with three sharp teeth, papilla small and round, 

 armed with long setae; two pairs of postmaxillary spines sharp. 



Figure 45. — Argulus notilis: a, Kespiratory areas; Ty, ribs of suction cups; c, accessory 

 organs of last three legs of male. 



First two pairs of swimming legs with flagella ; anterior distal end 

 of proximal segment of endopod with a fingerlike projection; boot- 

 shaped lamella on posterior coxa of fourth legs of female, lamella 

 merely prolonged laterally on the male. Male first appendage with 

 posterior lamella on coxa and a row of setae along posterior ventral 

 edge ; second appendage with usual bilobed lamella on coxa but distal 

 end with perpendicular papilla, proximal part of lamella saddle- 

 shaped from a lateral view (fig. 45, c) ; coxa of third has a long finger- 

 like flap extending from the anterior distal edge of the segment over 

 the basis to the expod ; posteriorly the coxa is fringed with long setae. 

 The socket is indicated by a rounded pocket on the posterior margin 

 of the basis ; the endopod is bent posteriorly at its origin and bowed 

 anteriorly toward the joint. The fourth appendage has a lamella 

 bearing setae on the posterior edge of the coxa, which is prolonged 



