COPEPODS OF THE WOODS HOLE REGION" 



125 



segment on both sides ; there is a stout fingerlike process on the right 

 side of the anal segment near the center. Total length, 4rA.S mm. 



Remarks. — The sharp process on the forehead will distinguish this 

 species. It is evidently a bottom form and has been obtained from 

 various depths up to 1,500 meters or more. 



PLEUROMAMMA ABDOMINALIS (Lubbock) 



Figure S3 



Diaptomus abdoDrhiale LtmBOOK, Trans. Ent. Soc. Loudou, new ser., vol. 4, p. 28, 



pi. 10, figs. 1-8, 1856. 

 Pleuromamma abdominalis Giesbkecht and Schmeil, Das Tierreich, Lief. 6, 



Copepoda, p. 109, 1898. 



Occurrence. — Five females from trawl wings. Stations 2195, 2219, 

 Albatross, south of Nantucket and Marthas Vineyard. 



Distrihution. — Northern Atlantic (Lub- 

 bock) ; Mediterranean (Claus, Giesbrecht) ; 

 Hawaiian Islands (Brady) ; Canary Islands, 

 Malta (Thompson) ; tropical Pacific (Gies- 

 brecht) ; Malay Archipelago (A. Scott) ; Gulf 

 of Maine (Bigelow). 



Color. — Body fairly transparent and color- 

 less, with red pigment flecks in varying num- 

 bers, especially in the region of the mouth. 

 The skin glands are often greenish yellow and 

 the region of the genital opening is dark 

 brown or even black; eye ruby red. The 

 luminous organ is very dark and in preserved 

 si^ecimens nearly always turns black. 



Female. — Head fused with the first seg- 

 ment; basal segment of first antenna with 

 several small and two large teeth on its an- 

 terior margin ; urosome half as long as meta- 

 some ; fifth legs 4-segmented ; second and third 

 segments each with an outer seta; third and 

 fourth segments with an inner fringe of hairs ; 

 end segment obliquely truncated, with three 

 apical setae, the inner one longer than the leg itself, the other two 

 very much shorter. Total length, 2.4—3 mm. 



Male. — ^Larger and a little stouter than the female basal segment 

 of first antenna with small teeth only, no large ones ; grasping antenna 

 on right side; luminous organ and invaginated second endopod on 

 left side ; right second endopod not invaginated at the base ; urosome 

 asymmetrical, twisted to the left ; fifth legs 5-segmented, fourth seg- 

 ment of left leg and third segment of right leg with a stout, pointed 

 process on the inner margin ; end segment of left leg short, wide, and 

 71937-^2 10 



Figure 83. — Pleuromamma 

 abdominalis: a, Male, 

 fifth legs ; h, female, fifth 

 legs 



