REPORT ON THE COPEPODA. 3 



here tabulated, only one (Euchceta prestandrece) was found in all the seven districts, but 

 no fewer than nine species occurred in all but one of the areas ; these being Calanus 

 propinquus, Eucalanus attenuatus, Scolecithrix dance, Pleuromma abdominale, Undina 

 damvinii, Centropages violaceus, Candace truncata, Corycceus varins, and Onccea obtusa. 

 Undina damvinii, Scolecithrix dance, Centropages violaceus, Corycceus varius, and Onccea 

 obtusa were not found in the Southern Indian Ocean ; but this area was not investigated 

 north of latitude 43° S., and it is more than likely that the tropical zone of that ocean 

 would have produced these species abundantly. Pleuromma abdominale was wanting in 

 the gatherings from Eastern Asia, and Candace truncata from the South Pacific. All 

 nine species usually occur in considerable abundance, excepting, perhaps, Centropages 

 violaceus, which is certainly much scarcer than the rest. The area producing the 

 smallest number of species (fifteen), is the South Indian Ocean, doubtless for the reason 

 already stated ; from the North Pacific the number is not much greater, twenty-two. 

 Leaving out of consideration the fish-parasites, the largest numbers of species were 

 obtained from the North Atlantic, South Atlantic, Eastern Asiatic, and Australasian 

 seas, the numbers from each of these areas being forty-eight, forty-eight, forty-five, and 

 forty- two respectively. The only undoubted deep-sea species is Pontostratiotes abyssicola, 

 the single specimen of which — dredged in a depth of 2200 fathoms — was picked from the 

 dried mud, having unfortunately lost much character in the drying process. Some others 

 were got in deep hauls of the tow-net, but these were usually either well-known species, 

 or so much battered as to make recognition impossible, and it is very likely that most of 

 them were captured during the passage of the net towards the surface. Calanus princeps 

 may, however, be noted as an exception to this statement, the two or three specimens 

 from which our knowledge of the species is derived, having come up with deep hauls of 

 the dredge, and most probably from the very depths of the sea. Possibly we might also 

 include amongst abyssal species Hemicalanus acideatus, Phyllopus bidentatus, and one or 

 two Euchwtw (see lists, pp. 19 and 22), but it is not by any means certain that these 

 specimens came from the bottom. 



The fish-parasites are remarkably few, considering the attention which was paid to 

 ichthyology, and the considerable number of fishes captured during the expedition. All 

 the species that have come under my observation are noted in these pages. 



