COPEPODS OF THE WOODS HOLE EEGION 



147 



symmetrical ; caudal rami short, triangular : fifth legs asymmetrical, 



left larger than right, endopods rudimentary, little more than knobs, 



exopods 1-segmented, each 



ending in three unequal spines, 



with two minute spinules on 



the outer margin. Total 



length, 2.75-3 mm. 



Male. — Body shorter and 

 narrower than that of the 

 female; posterior corners of 

 fifth segment produced into 

 short lobes; urosome longer 

 and narrower than in the 

 female, and symmetrical ; 

 right fifth leg longer than left, 

 hand of chela only moderately 

 stout, with two thumbs, side 

 by side and equal in length, 

 and a strongly curved finger, 

 which shuts down between 

 the thumbs; end segment of 

 left leg conical. Total length, 

 2.5-2.75 mm. 



Rertiarhs. — This is a rare species and does not occur anywhere 

 except in very small numbers; it has not before been reported from 

 American shores. It may be distinguished by the 2-segmented sym- 

 metrical urosome of the female and by the fifth legs of both sexes, 



LABroOCERA AESTIVA Wheeler 



Figure 100 



Labidocera aestwa Whbieiler, Bull. U. S. Fish. Comm. 1899, vol. 19, p. 178, 

 fig. 16, 1900. 



Occurrence. — One female in surface tow on Georges Bank, Sep- 

 tember, 1872; 500 males and females in surface tow in Vineyard 

 Sound, August, 1875; 2,500 males and females by V. N. Edwards in 

 Vineyard Sound, December, 1877 ; 1,500 males and females by Rath- 

 bun in Vineyard Sound, August, 1881, August, 1882, October, 1882; 

 3,000 males and females by V. N. Edwards in Great Harbor, Woods 

 Hole, September, 1887; 5 females in surface tow, Newport Harbor, 

 by Rathbun, September, 1880; 9 males and females from trawl 

 wings. Stations 955 to 960, Fish Hamk, off Nyes Neck, Buzzards Bay. 



Distribution. — Gulf of St. Lawrence (T. Scott, Willey) ; Northum- 

 berland Strait (Willey) ; Gulf of Maine (Bigelow) ; Woods Hole 

 Harbor (Fish). 



FiGDRE 99. — Lahidocera nerii: a. Female, dor- 

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

 legs (after Giesbrecht) 



