COPEPODS OF THE WOODS HOLE REGION 35 



oviducts have a whitish tint, there is a large spot of faint reddish 

 yellow above the mouth, while the third, fourth, and fifth segments 

 of the right antenna and the eye are bright ruby red. In the text 

 Giesbrecht said that the red in the antenna was sometimes present 

 on both sides, sometimes on one side only, and sometimes entirely 

 lacking. 



Female. — Body slender and elongated, the greatest width not ex- 

 ceeding a quarter of the length; the fused head and first segment 

 nearly twice as long as the rest of the metasome; second, third, and 

 fourth segments each with two small dorsal and two lateral spines 

 on its posterior margin; genital segment with two similar dorsal 

 s|)ines near the middle of the segment; fifth legs with one seta on 

 the second segment and three on the third segment, the outer one 

 nonplumose and spiniform; caudal rami slightly asymmetrical. 

 Total length, 4^5.5 mm. 



Male. — Body similar to that of the female but the first antennae 

 considerably shorter ; left fifth leg biramose, endopod three times the 

 length of the exopod and made up of two segments of about the 

 same length; exopod 1-segmented, tipped with a long plumose seta 

 and a much shorter nonplumose one outside of it. Right leg unira- 

 mose, tipped with a stout curved claw. Total length, 3-4 mm. 



Remarks. — Although all Rathbun's specimens were obtained from 

 the trawl wings, the species is also commonly found near the surface. 

 It has come to be recognized as a regular factor in the fauna of the 

 Woods Hole region, but apparently it is always rather scarce. 



RHINCALANUS CORNUTUS Dana 



Figure 19 



Rhincalanus cornuUis Dana, United States Exploring Expedition, 1838-1842 

 (Wilkes), vol. 14, Crustacea, p. 1083, 1853, pi. 77, fig. 2, 1855.— Giesbeecht 

 and ScHMEiL, Das Tierreicli, Lief. 6, Copepoda, p. 23, 1898. 



Occurence. — Fifteen females from the trawl wings at Stations 

 2195, 2224, 2230, 2236, Albatross, south of Marthas Vineyard. 



Distribution. — Gulf of Guinea, Sulu Sea (Dana) ; Canary Islands 

 (Lubbock, Thompson) ; Philippines (Brady) ; tropical Atlantic and 

 Pacific (Giesbrecht, Cleve, Dana) ; Malay Archipelago (Cleve) ; 

 Gulf of Maine (Bigelow). 



Color. — Entire body transparent and colorless except a vertical 

 dash of reddish orange at the posterior margin of each segment on 

 either side, and a crimson tinge at the base of the mouth parts. Eye 

 spot elongate-oval, deep red, and rather minute. 



Female. — Frontal projection of head anchor-shaped, the rostral 

 filaments plainly visible in dorsal view; first antennae much longer 

 than the body; each posterior corner of the second, third, and fused 

 fourth and fifth segments armed with a stout spine, with two others 



