COPEPODS OF THE WOODS HOLE REGION 



313 



Distribution. — Mediterranean (Claus) ; North Atlantic (Farran) ; 

 coast of Norway (Sars) ; Chesapeake Bay (Wilson). 



Color. — Body very transparent and nearly colorless, but with a 

 light orange tinge around the mouth and along the sides of the head. 

 There is often a large oil bubble in the posterior part of the metasome 

 and two smaller ones between the head and the first segment; eye 

 orange-red. 



FeTTiale. — Body slender, metasome fusiform; rostrum strong, spini- 

 f orm, and nearly straight ; no highly colored plumes ; urosome about 

 as long as metasome ; genital seg- 

 ment dilated anteriorly; caudal 

 rami as long as anal segment and 

 divergent, the two middle apical 

 setae twice as long as the uro- 

 some, with scattered plumes. 

 First antennae reaching the sec- 

 ond abdominal segment; spines 

 on exopods of swimmings legs ar- 

 ranged as in flumifera. Ovisacs 

 extending outward nearly at right 

 angles to the body axis. Total 

 length, 1.25-1.4 mm. 



Male. — Much smaller and 

 stouter than the female, the fore- 

 head obtusely truncated, without 

 any trace of a rostrum; urosome 

 less than three-fifths the length 

 of the metasome ; genital segment 

 much enlarged ; caudal rami 

 shorter than the anal segment 

 and parallel. First antennae 

 twice geniculate, but without any trace of the sheath or the semicircu- 

 lar process found in flwmifera; setae of fifth legs much shorter than 

 in the female. Total length, 0.75-0.85 mm. 



Remarks. — Sars positively identified his Norwegian specimens 

 with the species originally described by Claus. If this is correct, the 

 new specific name atlantica proposed by Farran must yield prece- 

 dence to the one first given to the species by Claus. Sars said of this 

 copepod : " To judge from the structure of the oral parts, the animal 

 must be of a very rapacious nature, probably feeding upon other 

 small pelagic animals." ^° 



Figure 188. — Oithona spinirostris : a. Fe- 

 male, dorsal ; b, female, fifth leg 



" Crustacea of Norway, vol. 6, p. 7, X9i%^. 



