716 PROCEEDINGS OF THE NATIONAL MUSEUM. 



regular i^eg and semen vesicle this species shows a number of protu- 

 berances on the legs of the male; the basal joint of the second pair has 

 a rounded knob on the anterior surface next the body, and on the pos- 

 terior surface at the distal end another rounded knob, and outside of 

 this a long, finger-like projection. Both basal joints of the third pair 

 have conical projections extending diagonally outward from their 

 distal ends, that on the first joint being anterior and on the second 

 joint posterior. The second joint of the last pair of legs also has a 

 rounded knob on its posterior surface, and the peg on this joint is a 

 spherical ball. 



The posterior chitin ring in the carapace lobes is very broad, and its 

 anterior end is slightly concave and extends diagonally outward and 

 forward from near the base of the first pair of legs. Into the concav- 

 ity fits the very much smaller anterior ring, so that the two form a 

 symmetrical outline. 



Color of alcoholic specimens a yellowish white, thickly spotted with 

 brown over the entire dorsal surface and on the ventralsurface of the 

 abdomen, whence the name maculoMis, spotted. 



Length, 9.8 mm; length of carapace, 7.8 mm.; breadth of carapace, 

 7,9 nun; length of abdomen, 2 mm; breadth, 2.1 mm. Male about 

 two-thii-ds this size. 



The National Museum collection contains two lots of this species, 

 one consisting of 14 specimens, 11 females and 3 males, unlabeled, 

 the other a single female taken by Fred Mather from J^sox noUlior 

 Thompson, at Clayton, New York, and numbered 12226. This iden- 

 tifies it as a fresh-water species, which is also indicated by its close 

 reseml)lance in many particulars to the two following species. In all 

 probability it can be found upon the nuiscalonge elsewhere. 



ARGULUS VERSICOLOR, new species. 

 Plate XX; Plate XXVI, fig. S3. 



Carapace orbicular, about as wide as long; posterior sinus one- 

 third the length of the carapace, twice as long as wide. 



Abdomen ovate, three-sevenths the length of the rest of the body, 

 longer than wide; anal sinus very narrow and slit like, only reaching 

 one-sixth the length of the abdomen; papilhe subterminal. Sucking 

 disks medium size, very symmetrically placed far apart, near the 

 anterior edge of the carapace; posterior maxillipeds also medium size, 

 well armed; basal plate somewhat wedge-shaped, with long and blunt 

 teeth. 



Antenna' large, long, and armed with powerful hooks and very long 

 sharp spines, those at the base of the second antennte reenforced by 

 otlun- smaller ones. Proboscis long and wide, sting narrow and very 

 sharp. Swimming legs reaching far beyond the edge of the carapace, 



