COPEPODA. 33 



XANTHOCALANUS (Giesbrecht). 



There ;irc only two examples of this genus iu the ' Discovery ' collection. Since 

 the publication of Giesbrecht and Schmeil's " Copepoda " (in " Tierreich ") the genus has 

 received many additional species. To the originally described species, vi:., X. a</ilis 

 and A" minor (Giesbrecht), are now added X. Imrenlls (Sars), X. pruplnqaas (Sars), 

 X. muticus (Sars), X cristatus (Wolfendeu), X. suhcristatus (Wolfenden), X. simplex 

 (Wolfenden), X. matjnus (Wolfenden), X. calnminus (Wolfenden), X. atlanticus 

 (Wolfenden), A^ (/reeni (Farran), X. piu(juis (Farran), and A", ohtasas (Farran) ; and, 

 as they are described in scattered publications, it may be well to recapitulate the 

 characters here. 



1. X. AGILIS. 

 X. agilis, Giesbrecht, Fauna ii. Fl. Neap. XL\. (IS'Jl'), p. I'SG. 



Size 2" 4 ; furcal segments broader than long, abdominal segments very hirsute ; 

 anterior antennae reaching end of furca ; fifth feet three segments, beset with spines 

 and teeth, and ;tvith three apical teeth. 



In the i only one (the left) foot five-jointed. (Mediterranean.) 



2. X. SUBAGILIS. 



X. snluiffilis, Wolfenden, Jour. Mar. Biol. Assoc, VII. (19(»4), p. 118. 



Size 2 "6 mm., resembling X. agilis, but abdominal segments not hirsute. 



Fifth feet with three segments, the basal with strong teeth, the middle with only 

 hairs, the distal .spiuulose and with three long apical spines. 



(? with a pair of fifth feet nearly equal, the right of four, the left of five 

 segments. (Mull of Galloway.) 



3. X. BOREALIS. 

 X. bonealis, Sars, Crustacea of Norway, Vol. IV., p. -iC. 



Size 3 '50 mm. ; furcal segments as broad as long, anterior antenna} reach end of 

 genital segment ; fifth feet of three segments, proximal two, with teeth on inner 

 margin ; last with two apical and two lateral spines. 



$ with a pair of fifth feet left of five segments, right very short and of only three 

 segments. (Polar Seas. Norway.) 



4. X. PROPINQUUS. 

 X. propiiiquus, Sare, loc. cit. 



Size 175 mm. ; furcal rami longer than l)road; anterior antennae slender and 

 reaching only to .second abdominal .segment, posterior antennai with Re much longer 



