484 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



small, second antennae long (fig. 25, c). All spines are dark colored. 

 Suction cups moderate, rim narrow, ribs composed of three rods, 

 marginal lappets long (fig. 25, 6). Second maxillae slender, basal 

 plate with three large teeth; two pairs of prominent postmaxillary 

 spines. 



Thoracic appendages very long, first pairs with flagella; slight 

 prominence with setae on the distal posterior surface of the coxa of 

 third appendages on female; prominent boot-shaped natatory lobe 

 on posterior of fourth appendages extending laterally as far as the 

 base of the rami, with the heels pressed against the posterior end 

 of the thorax; slight setose posterior lobe on the basis. 



ARGULUS FLAVESCENS Wilson 

 FiGUBE 26 



Argulus flavescens Wilson, 1916, p. 349, pi. 61, figs. 7-12.— Mueller, 1936, p. 807. 

 Argulus piperatus Wilson, 1920a, p. 149, figs. 1-7. 



Carapace longer than wide, sinus more than one-third the length; 

 abdomen ovate on female, elliptical on male, lobes rounded and often 

 touching on the inner margins on the female, sinus giving the im- 

 pression of being wider at the base; anal papillae basal, small, and 

 rounded. 



On the type there are lateral expansions into the carapace. These 

 are called "lateral lobes of the stomach" by Wilson, but they are 

 really expansions from the egg-filled ovaries. They occur only on 

 gravid females, while those partially spent may have one side filled 

 or only a few eggs remaining. Thiele noted these expansions on 

 A. africarvus in the Berlin Museum. 



The anterior respiratory area is small and subtriangular, while 

 the other is very large with a broader posterior portion (fig. 26, h). 

 The females reach up to 6 mm., while the males are smaller. 



First antennae with a slender lateral claw, anterior knob with a 

 slight hook, flagellum about the length of lateral hook, tip biramous. 

 Second antennae long, distal joints slender, spine at base; postan- 

 tennal spines long and larger than others; ventral surface of distal 

 segments armed with setae. 



Suction cups with the ribs on the rim made up of four to six rods, 

 the distal ones somewhat compressed (figure 26, c). Second maxillae 

 with three blunt teeth on the basal plate, long setae on the pad of the 

 basal disc (fig. 26, a). Postmaxillary spines fairly long. On southern 

 specimens any or all may have a worn appearance. 



