COPEPODA. 
31 
Second feet, Ri distinctly two-jointed. 
Third and fourth feet, Ri and Re of three joints each. B 2 of the fourth feet with 
tubal bristles as in Gaidius. 
The extraordinary size of this animal makes it the largest known species of 
Gaetanus. It occurred once only in the ‘ Discovery ’ collection, and also appeared in 
the ‘ Gauss ’ collection, and is probably Antarctic in its habitat. Several new species of 
Gaetanus have been described recently, and it may serve some useful purpose to 
recapitulate here the different species discovered since Giesbrecht and Schmeil’s last 
work (Tierreich, 1898). 
1. Gaetanus major. 
G. major, Wolfenden, Proc. Zool. Soc., London, Feb. 3, 1903, in Dr. Fowler’s paper. 
„ Farran, Ann. Rep. Fish. Ireland, 1902-03, Part II., App. II., 1905. 
Size 5 mm. and over. Anterior antennse larger than the body by about one joint; 
lamellar appendage of posterior foot jaws absent; Re of first feet of three segments, 
and with three Se. Cephalic spine short, and as in G. armiger. 
2. Gaetanus caudani. 
Gaetanus caudani, Canu, Ann. Univ. Lyon, V. 26, 1896. 
„ „ Wolfenden, Jour. Mar. Biol. Assoc., 1901, p. 21. 
,, (?) pileatus, Farran, ibid. 
Like G. miles, but anterior antennse only one-and-half times as long as the body ; 
lamella of posterior foot jaw like that of G. miles. Re of first feet, three segmented 
basals of fourth feet with tubal bristles, 5 mm. and over. Canu’s original description 
was of one immature $ . Farran’s were also immature specimens. 
3. Gaetanus holti. 
Gaetanus holti, Farran, ibid. 
„ latifrons, Sars, Bull. Mus. Monaco, No. 26, March, 1905. 
„ longispinus, Wolfenden, Plankton Studies, Part I. (1905), p. 7. 
Cephalic spine strong and directed backwards with long interval between the 
frontal part and base of the horn. Anterior antennse not as long as the body-spines of 
the last thoracic segment, strong, long, and directed backwards. Small lamella on 
posterior foot jaw. First feet with three segments and three Se. Fourth feet with 
basal tubal bristles. Size 4 • 74 mm. 
4. Gaetanus antarcticus. 
Gaetanus antarcticus, Wolfenden, Plankton Studies, Part I. (1905), p. 7. 
Thorax gibbous, very stout short curved cephalic spine directed forwards, head 
square, not like G. armiger. Abdomen short and thick, not a quarter of whole length. 
