COPEPODS OF THE WOODS HOLE REGIOl^T 



95 



Color. — Body a light transparent blue, the first antennae having 

 the same color at the base. The blue color of the body reaches the 

 last metasome segment, and there changes to a light bright orange- 

 yellow, sometimes a lemon-yellow, irregularly edged behind and 

 below with a deep orange-red. The yellow often occurs also on the 

 ventral and lateral margins of the preceding segments. The urosome 

 segments present a combination of orange-yellow and the brightest 

 deepest red imaginable, being lightest near the metasome and deep- 

 est toward the anal segment. The colors vary greatly as to intensity ; 

 sometimes the first 2 or 3 segments contain but little red, but the 

 last segments are always of a deep color. On the anterior urosome 

 segments the red usually is most 

 intense near the posterior mar- 

 gin, often leaving but little 

 yellow. 



In the first antennae 4 or 5 of 

 the basal segments are blue; 

 then begins orange-yellow, with 

 some red on the upper and outer 

 margins of the segments. The 

 color then grows deeper, the red 

 gradually overshadowing the 

 yellow, the segments being most 

 deeply colored outwardly. At a 

 point about two-thirds of the 

 leng-th of the antenna the yellow 

 disappears, and the red becomes 

 as deep and intense as at the tip 

 of the urosome. The posterior 

 legs are yellowish, the remain- 

 ing appendages light blue and 

 transparent, with the last one or 

 two segments -yellowish, sprin- 

 kled with small spots of red, which are larger and brighter on the 

 mouth parts than on the legs. 



Eye spot large, irregular in shape and crystal red; front part of 

 the head around it colorless. A little yellow is usually scattered 

 through the blue of the body, but is nowhere at all prominent. It 

 is impossible adequately to describe the appearance of this copepod, 

 which far exceeds in beauty any of the marine forms thus far 

 obtained (Kathbun). 



Feviale. — Head fused with first segment; fourth and fifth seg- 

 ments also fused, with rounded posterior corners; genital segment 

 not quite so long as the abdomen and usually divided near the center 

 as in the figure; inner margins of the caudal rami ciliated. First 



Figure 64. — Diaptomus leptopus: a, Male, 

 dorsal ; b, female, fifth legs ; c, male, fifth 

 legs 



