REVIEW OF GENUS ARGULUS — MEEHEAN 



485 



Swimming appendages with flagella on the two anterior pairs. 

 Second pair of male appendages with a posterior lobe on the ventral 

 side of the precoxa, and the usual spinous pad on the coxa (fig. 26, d). 

 Third pair of male appendages with a broader lobe on the posterior 

 of the precoxa than on the preceding appendages and a long lobe over 

 the coxa and basis that contains the socket. The peg is located on the 

 distal anterior angle of the basal segment with a very broad base. It 



FiGCEB 26. — Argulus flavescetis: a. Basal plate of second maxillae and mesial spines; 

 b, respiratory areas ; c, ribs of suction cups ; d, ventral view of male accessory organs 

 of last three legs. 



is divided longitudinally into two parts. The distal portion is slender, 

 while the proximal portion is broad with a broad bluntly rounded tip 

 and with transverse bands or chitinous ribs. On the ventral surface 

 is a fleshy lobe directed obliquely toward the appendage much like 

 that of A. japonicus. There is the usual chitinous ridge around the 

 base of the peg, and a boot-shaped (in some cases more rounded) 

 posterior lobe on the coxa. The total length of the basal segments 

 of the three posterior appendages is progi-essively shorter toward the 

 posterior. A large lobe is located at the opening of the ejaculatory 

 duct. Both sexes are flecked with pigment. 



