872 CRUSTACEA. 



inferior, of fifteen to eighteen joints in the male, and about fourteen 

 in the female. 



Male. — The claw of finger of hand of first pair of feet is not as long 

 as the apical margin. The finger of second pair when closed, extends 

 half way or rather more toward base of hand; the hand is naked, 

 except the minute spinules or setae on the palm. The third and 

 fourth pairs of legs are very slender ; the fifth is much longer than 

 half the seventh ; the seventh is longer than the sixth. The setules 

 of the legs of the fifth joint of the seventh pair are nearly alike on 

 both margins, and about one-fourth the diameter of the joint in length. 

 The tarsus is straight and slender. 



0. serrulata, Dana, Proc. Amer. Acad. Sci., ii. 204. 



Orchestia tenuis. 



Feminae : — Epimerce sat breves. Antennae 2do3 tenues, dimidii corporis 

 longitudme, flagello tenidssimo, valde longiore quam basis, articulis 

 oblongis, cylindricis, setis articido vix brevioribus. Antennae lmo3 basi 

 2darum vix breviores. Pedes 4 antici debiles; primi minimi; secundi 

 parvuli, manu minutd, oblongd, retrorsum inflexd, extremitate dimidio 

 truncatd, apice inferiore producto et obtuso, digito minuto, fere tram- 

 verso, ab extremitate paulo remoto. Pedes 4 sequentes parvidi, itis 

 brevioribus. Pedes 6 postiei sensim increscentes, Imis fere duplo Ion- 

 gioribus quam 6ti; setis brevibas, articuli diametro non longioribus. 



Female : — Epimerals rather narrow. Inferior antennae slender, about 

 half as long as body, flagellum very slender, much longer than base, 

 joints oblong, setae hardly shorter than joints. Superior antennae 

 about as long as base of inferior. Four anterior pairs of feet quite 

 small and weak; first pair much the smallest; hand of second pair 

 very small, oblong, bent backward, truncated half across towards 

 apex, finger minute, rather remote from extremity and nearly 

 transverse ; third and fourth pairs small ; the fourth pair smaller 

 than third ; three posterior pairs very unequal, increasing regularly 

 in length ; seventh pair nearly twice longer than fifth, setae short, 

 scarcely longer than diameter of joints. 



