400 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxm. 



identified by Brady with Dana's species, which came from exactly 

 the same locahty. It is now made the type male of Pandarus hrevi- 

 caudis, the perfect agreement in anatomy being sufficient to identify 

 the two specimens as male and female of the same species. Further- 

 more, Dana's original specimens of Nogagus validus and Pandarus 

 hrevicaudis were found together on the same fish. 



PANDARUS BICOLOR Leach. 



Plate XXVII. 



Pandarus bicolor Leach, 1816, p. 405, pi. xx, 2 figs. 

 P. boscii Leach, 1816, p. 406, pi. xx, 10 figs. 

 Caligits bicolor Lamarck, 1818, p. 142. 

 Pandarus fissifrons Milne Edwards, 1840, p. 470. 



Female. — Body elongate, length more than twice the width; 

 carapace semielliptical, one-third the entire length, widest across the 

 posterior margin. Frontal plates wide and prominent, the groove 

 between each frontal plate and the margin of the carapace S-shaped, 

 the center of the carapace projecting as a knob on either side of the 

 central incision between the frontal plates. 



Posterior lobes short and broad; posterior margin a nearly uniform 

 curve, the center of which is sinuate, but not toothed. 



Dorsal plates of second thorax segment short and narrow, not 

 reaching the tips of the plates on the third segment and fused across 

 the mid-line, their posterior margins forming an evenly rounded 

 semicircle, without any break that can be detected. 



Second pair of plates nearly circular, with a deep and broad 

 median incision, which is somewhat enlarged at its base. These 

 plates reach back a little beyond the first pair. Third pair much 

 enlarged, elliptical, as wide as the carapace, and overlapping the 

 genital segment for about half its length. The central sinus is deep, 

 broadly triangular, and rounded at its base. 



Genital segment elliptical, one-fifth narrower than the carapace, 

 with broadly rounded posterior lobes and a shallow sinus. 



Sixth segment plate half the width of the genital segment, its 

 posterior two-thirds the evenly rounded arc of a circle, its anterior 

 third fitting into the sinus in the genital segment. 



Abdomen medium size, its ventral plate quadrangular, with tlie 

 free portion broadly rounded and the posterior margin slightly 

 concave. Anal laminfe triangular, as wide at the base as they are 

 long, extending out at right angles to the median axis and so short 

 that they scarcely reach the lateral margin of the genital segment? 

 They are not toothed, but have smooth edges. 



First antennae small, the whole basal and part of the terminal 

 joint concealed beneath the frontal plates, neither joint heavily 

 armed with setae. Second pair small, the basal joints not much 



