52 BRITISH OOPEPODA. 



Head united with first ring of thorax, or only in- 

 distinctly separated. Anterior antennae as long as the 

 cephalothorax, the right of the male having nineteen, 

 the left twenty-one joints ; many of the antennal 

 joints in both sexes much swollen at the apices, giving 

 the organ a knotted appearance, the whole being beset 

 with scattered hairs, some of which are excessively 

 long : the ninth to the thirteenth joints of the male 

 right antenna are much swollen to provide for the 

 internal muscular apparatus, and the hinge is situated 

 between the fourteenth and fifteenth joints (figs. 2, 3, 

 4) . Anterior foot-jaw approaching in appearance that 

 of Pontella, its numerous strong setge being armed 

 with short rigid divaricating hairs. Posterior foot-jaws 

 bearing on the basal joint a papilliform process which 

 supports a single very long seta and three smaller 

 ones ; the second joint has a single long seta which 

 also springs from the summit of a papilla ; the remain- 

 ing joints are smaller and bear small marginal spines. 

 Terminal spines of the swimming feet long, slender, 

 sword-shaped, and finely serrated on the inner border. 

 These spines are peculiar, for instead of having one or 

 more small supplementary spines at their base, con- 

 nected with the last segment of the foot by a movable 

 joint, as is usually the case, the spine is, in this species, 

 formed by a mere arched and pointed process of the 

 outer edge of the foot (fig. 11). The fifth feet in the male 

 consist each of a four-jointed branch, forming a pair of 

 strong crooked and prehensile claws (fig. 13), the inner 

 margins of which, especially on the right side, are pro- 

 duced into wart-like projections, and the terminal joints 



