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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



antennal spine and an extra one between that and the one at the base 

 of the first antennae, making tliree in a row. 



Suction cups have ribs made up of an oblong basal plate and two 

 to four somewhat oblong shorter ones (fig. 39, h). These differ from 

 maculosns in that the distal plates are oblong rather than rectangular 

 and the basal plate is long and narrow without a broad base. The 

 second maxillae have long widely spaced teeth, with the two pairs of 

 spines near the midline of the body stout and long, the posterior pair 

 very near the basal j)late. These teeth are slenderer than in mdculosus. 



Figure 39. — Argulus versicolor: a, Respiratory areas ; b, ribs of suction cups ; c, male 

 accessory organs of last three legs. 



Flagella are present on the swimming legs. There is a slight lamella 

 on the posterior of the coxa of the third appendages of the female; 

 the usual natatory lobe on the posterior of the fourth appendage but 

 without a heel; large females may have a lamella on the basis also, 

 tactile papillae very long. 



On the male the second appendages have the usual bilobed pad on 

 the posterior ventral side of the coxa armed with short spines (fig. 

 39, c). On the third appendages there is a lamella on the posterior 

 surface of the basis, with a rounded lobe on the coxa that accommo- 

 dates the socket. Dorsally there is a large rounded papilla on this 

 segment, with a groove running posteriorly to the opening of the 

 socket. The fourth legs of the male have a posterior lamella ex- 

 panded somewhat laterally over the basis. Anteriorly there is the 

 usual chitinous ridge medially around the base of the peg, while the 

 peg itself is pear-shaped, with a broad base and narrow tip projected 



