68 BRITISH COPEPODA. 
Genus 17. Diosaccus, Boeck (1872). 
Anterior antenna 8-jointed, the peduncle (first four 
joints) very long, flagellum (last four joints) short. 
Inner branch of the posterior antenna 1- or 2-jointed. 
Mandible-palp simple, 2-jomted. Outer branch of the 
first foot very short, 3-jointed ; inner branch 3-jointed, 
first jomt much elongated, second and third extremely 
short; second, third, and fourth pairs having both 
branches 3-jointed, except that the inner branch of the 
second pair in the male is 2-jointed ; ovisacs two. 
It is perhaps doubtful whether the characters of this 
genus are such as to warrant its separation from 
Dactylopus, the most important diagnostic marks being 
the elongated peduncle of the upper antenna, the 
1-branched mandible-palp, and the double ovisac. The 
only British species is Diosaccus tenwicornis, but M. 
Boeck has described a second species from Norway, 
under the name of D. abysst. 
1. Drosaccus Tenvrcornis, Claus. Pl. LIX, figs. 12—16, 
and Pl. LX, figs. 14-—18. 
Dactylopus tenuicornis, Claus. Die frei-lebenden Copepoden, 
p. 127, t. xvi, figs. 17—23 (1863). Cope- 
poden Fauna von Nizza, p. 28, t. iii, 
figs. 17—19 (1866). 
Nitokra = B. & R. Ann. and Mag. Nat. Hist., 
ser. iv, vol. xii, p. 187 (1873). 
Body slender, elongated, head united with first thora- 
cic segment, and produced into a long curved beak (PI. 
