410 PROCEEDINOS OF THE NATIONAL MVSEUM. vol. xxxm. 



There is also a single female, Cat. No. 8118, U.S.N.M., collected 

 by Francis Day from Lamna cornuhica, and another female, Cat. No. 

 6831, U.S.N.M., from a species of Carcharhinus between Papua and 

 Japan, obtained by exchange from G. S. Brady, and collected during 

 the CJiallenger Expedition. 



PANDARUS SMITHII Rathbun. 



Plates XXIX and XXX. 



Pandarus smithii Rathbun, 1886, p. 315, pi. v, fig. 3; pi. vii, fig. 9. 



Female. — Carapace ovate, a little wider than long, the anterior mar- 

 gin evenly rounded, the lateral margins convex; posterior lobes short, 

 wide, and bluntly rounded; posterior margin between the lobes sin- 

 uate and wrinkled, each wrinkle ending in a sharp, spine-like tooth. 

 Frontal plates broad and prominent, much wider at the outer ends 

 than near the median line, and covering nearly the whole of the basal 

 joints of the first antennae. Eyes nearly always concealed by the dark 

 pigment of the carapace, but sometimes visible two-fifths of the length 

 of the carapace from the frontal margin. 



Three distinct dorsal plates on the second thorax segment, the lat- 

 eral pair elongate, elliptical, or ovate, about twice as long as wide, and 

 strongly divergent. The odd plate median semielliptical or subtri- 

 angular, and about half the length of the lateral plates. Dorsal plates 

 of the third segment almost circular in outline, less than half the length 

 of the first pair, and completely separated to their base, often leaving 

 a wide, open space between their inner margins. Dorsal plates of the 

 fourth segment much enlarged, broadly rounded, and separated by a 

 triangular posterior sinus of medium depth. These plates overlap 

 the genital segment at least beyond its center, and often nearly to its 

 posterior margin. 



Genital segment obovate to elliptical, narrower than the plate on 

 the fourth segment, and ending posteriorly in a short, rounded knob at 

 either corner. Sixth segment plate ovate, strongly narrowed ante- 

 riorly, projecting for two-thirds of its length back of the genital seg- 

 ment, with an evenly rounded margin. 



Abdomen small, its ventral plate of the usual shape, but not reach- 

 ing beyond the center of the sixth segment plate; anal laminae the 

 same length as the sixth segment plate, diverging at an angle of 45° 

 to the body axis, so that almost the entire lamina is visible from 

 above. Of the two wings on the inner margin, the dorsal runs the 

 entire length of the lamina and is of the same width throughout; it is 

 cut off obliquely at the tip, and the cut edge is more or less lacerated 

 and armed with two or three small spines. The ventral wing is semi- 

 circular in shape and occupies only the basal half of the lamina; its 

 margin is smooth and without spines. The combined width of the 



