PA RASITK ' < '()Pf:f'ODS—('ATJ(;TD.J^— WILSON. 597 



jointed and two of the five spines belong to the second and third joints, 

 respectively. The carapace also is almost exactly as here tig-ured, and 

 the furca differs only in having- the base a little longer. Both Scott 

 and Bassett-Smith figure the abdomen as one-jointed, but neither of 

 them makes any statement in regard to it. In ))oth figures, however, 

 the abdomen narrow^s abruptly near the posterior end at exactly the 

 place where the joint occurs in the present species. 



Bassett-Smith makes no statement of the dimensions of the speci- 

 mens he obtained, but in his explanation of the plate the magnification 

 of the figure is given as 6. This would give a length of 7 nun. Scott 

 states that the single specimen he o])tained was 5.. 5 mm. In the pres- 

 ent species no specimen thus far obtained has exceeded 4 nun. 



In view of these meager and conflicting- descriptions, together with 

 the contradictions expressed in the figures, it becomes practically 

 impossible to decide just how many species are represented. The size 

 given for O. scomherl" seems to preclude its identity with peJcDiiydis, 

 and yet the two agree in almost every detail as given l)y the one or 

 the other of the two authors quoted. 



It will require a careful comparison of the original types to decide 

 the problem finally. 



CALIGUS PRODUCTUS Dana. 



Plate XIY, figs. 162-170. 



Caligus produchts Dana, 1854, p. 135-i, pi. xciv, fig. 4.— Steenstrup and Lutken, 

 1861, p. 357, pi. Ill, fig. 6.— Kroyer, 1863, p. 64, pi. in, fig. 4, a-i.— Rath- 

 bun, 1884, p. 487.— Brian, 1898, p. 10. 



Female. — Carapace ovate, much less than half the entire length; as 

 long as wide, nai-rowed anteriorly. Frontal plates projecting strongly, 

 but not more than three-eighths of the width of the carapace. Lunules 

 small, orbicular, scarcely projecting. Posterior sinuses inclined out- 

 ward, and of medium width, leaving a median lobe less than half the 

 width of the carapace, and not projecting posteriorly. Lateral lobes 

 broad, well rounded, and turned inward slightly at the tips. Thoracic 

 area small, and contracted anteriorly. Eyes small, and placed well 

 back from the anterior margin. 



Free thoracic segment very narrow and spindle-shaped, al)out one- 

 fourth the width of the carapace, and contracted into a neck anteriorl}^ 

 where it joins the latter. Genital segment elliptical, with evenl}^ curved 

 sides, like the free segment contracted anteriorly Avhere it joins that 

 segment, and expanding abruptly to its full width. It is five-eighths 

 as wnde, and almost seven-eighths as long as the carapace. 



Abdomen elongate linear, somewhat swollen at the center, about one- 

 quarter longer than the genital segment, and more than four times as 



"This is Bassett-Smith' s spelling; Scott changes it to scombri. 



