598 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxni. 



times as long as wide, with a very simple bony framework indis- 

 tinctly jointed near the center. The framework consists of four 

 long bones, one on either margin of the upper and under lips. These 

 bones are jointed to other short oblique ones, which are fastened 

 to the ventral surface at the proximal end of the mouth tube. At 

 the distal end they are connected by a series of transverse bones very 

 similar to those found in Caligus curtus. The mouth opening is 

 terminal and reaches nearly the whole diameter of the tube. It is 

 surrounded with the usual fringe of long hairs. 



The terminal claws of the first maxillipeds have a narrow mem- 

 branous fringe along both margins. The second maxillipeds have 

 a stout and swollen basal joint, while the terminal claw is much 

 shorter, but strong and well curved. On the inner surface of the 

 basal joint near its proximal end there is an elevation, at the top of 

 which is a circular cup or pit, as though it were for the reception of 

 the terminal claw, but the latter is not long enough to reach it. The 

 fru'ca is entirely lacking. 



The first legs are small and weak, the l)asal joint with a small 

 spine on its posterior border, the outer terminal claw twice as long as 

 the other two. The second legs are large and stout with especially 

 long and strong plumose setse. The spine at the tip of the basal 

 joint of the exopod is toothed along its inner margin, while the one 

 on the second joint is toothed along both margins. The apron of the 

 third legs is much longer than usual, making with the long set* of 

 the second legs powerful swimming organs. The rami of these third 

 legs are very widely separated, the exopod three-jointed and approxi- 

 mated closely to the margin of the apron, but even then it does not 

 cover half the distance to the two-jointed endopod. 



The fourth legs are small and weak, three-jointed with five spines, the 

 four outer ones about the same length, the one at the inner corner 

 somewhat longer. The fifth legs are near the posterior margin of the 

 genital segment on the ventral surface, and each shows two distinct 

 papillae standing side by side, the outer one carrying a single seta, the 

 inner and larger one carrying two. 



In fig. 24, showing the ventral surface of the genital segment, the 

 oviducts are just l)eginning to coil, and their entire contents are 

 granular. This specimen, therefore, is a young female which had 

 never borne eggs. The cement glands are narrow, parallel to each 

 other, and close to the mid line. The cellular part extends nearly to 

 the base of the glands, leaving only a very short and inflated duct. 

 The semen receptacles are of the usual spindle shape, comparatively 

 small and slender. 



On the external surface can be seen two spermatophores dis- 

 charging their contents into the sperm receptacles through the sexual 

 openings. 



