726 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



sharply marked off from the remainder of the carapace, and lunate or 

 semielliptical in .shape; posterior sinus broad triangular, less than a 

 quarter the length of the carapace, wider than deep. Abdomen ellip- 

 tical, two-fifths the length of the rest of the body; anal sinus broadly 

 triangular, cut to the center; lobes acute and flaring at the tips; 

 papillit' ])asal. Sucking disks large, one-quarter the width of the cara- 

 pace, situated far back, and widel}^ separated; posterior maxillipeds 

 small and pooi'ly armed; basal plate well rounded, with only two 

 teeth. Antenna^ large and well armed. 



Swimming legs long, reaching far beyond the carapace; lobes on 

 the posterior pair narrow sickle-shaped, much elongated. 



Color a fleshy pink, ornamented with lines and bands of dark pig- 

 ment; the latter include a broad longitudinal band between the eyes, 

 an oval area in the center of each carapace lobe, the two areas con- 

 nected by three transverse lines, and an oval area in the center of each 

 lobe of the abdomen, connected anteriorly by a single transverse line. 



Length 7 mm.; length of carapace 4.4 mm.; breadth of carapace 

 3 mm.; length of abdomen 2 mm.; breadth 1.3 mm. Male unknown. 



Habitat. — From Senegal, in the Bay of Dakar, on a species of shark. 



{MeUta = t\iQ name of the yacht of M. Chevreux, who found the 

 parasite and sent it to Van Beneden.) 



ARGULUS DACTYLOPTERI Thorell. 

 Plate XXIII, figH. 67, 68. 

 ArgulnH dactylopterl Tfiorell, 1864. 



Carapace elliptical; cepluilic area projecting considerably beyond 

 the outline of the remainder of the carapace, leaving ear-like append- 

 ages on either side. Those in the female are of medium size and are 

 situated in front of the sinus; those in the male are very large and 

 protrude posterior to the sinus, giving the anterior portion of the 

 carapace a three-lobed appearance. Posterior sinus broadly triangu- 

 lar, about as wide as deep, leaving well-rounded lobes. Abdomen 

 broadly triangular, about one-third the length of the rest of the bod}^; 

 anal sinus narrow, about one-third the length of the abdomen; lobes 

 rounded acuminate; anal papilla3 very minute and basal. 



Sucking disks small, less than one-sixth the width of the carapace; pos- 

 terior maxillipeds rather poorly armed; basal plate with minute teeth 

 along its outer l)order in addition to the three on its posterior border. 

 Antennaj with stout auxiliary spines in addition to the regular ones 

 on the basal joints. Swinnning legs without flagella; just reaching 

 the margin in the female, extending l)oyond in the male. 



Color grayish white in alcoholic specimens, the female with two 

 violet bands along the dorsal surface of the thorax made up of small 

 spots of the same color. 



Length 7-8 mm.; length of carapace 5 mm.; breadth of carapace 



