COPBPODA. 33 



XANTHOCALANUS (Giesbrbcht). 



There are only two examples of this genus in the ' Discovery ' collection. Since 

 the publication of Giesbrecht and Sehmeil's " Copepoda " (in " Tierreieh ") the genus has 

 received many additional species. To the originally described species, viz., X. agilis 

 and X. minor (Giesbrecht), are now added X. boreaiis (Sars), X. propinquus (Sars), 

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

 (Wolfenden), X. magnus (Wolfenden), X. calaminus (Wolfenden), X. atlanticus 

 (Wolfenden), X. greeni (Farran), X. pinguis (Farran), and X. obtusus (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 u. Fl. Neap. XIX. (1892), p. 286. 



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 with three apical teeth. 



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



2. X. SUBAGILIS. 



X. subagilis, Wolfenden, Jour. Mar. Biol. Assoc, VII. (1904), 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 spinulose and with three long apical spines. 



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

 segments. (Mull of Galloway.) 



3. X. BORBALIS. 

 X. boreaiis, Sars, Crustacea of Norway, Vol. IV., p. 46. 



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. propinquus, Sars, loc. tit. 



Size 1-75 mm. ; furcal rami longer than broad; anterior antennae slender and 

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



