464 G. STEWARDSON BRADY. 



Genus Diaptomus Westwood. 



Diaptomus pictus sp. nov. PL XXXIY, figs. 1-6. 



Female . — Body rather robust. Seen dorsally, the anterior 

 division is about three times as long as broad, nearly equal in 

 width throughout, rounded in front, the last segment produced 

 into two very conspicuous lateral flaps which are doubly 

 acuminate at the distal angle. Urosome biarticulate," the 

 anterior (genital) segment dilated basally, distal segment 

 longer ; caudal rami short, not much longer than broad, 

 terminal sette stout and strongly plumose. Anterior antennae 

 short, extending scarcely beyond the posterior extremity of 

 the cephalothorax. Basal joint of last pair of legs simple, 

 without any angular prominence ; inner branch simple, 

 uniarticulate, claviform, slightly shorter than the first joint 

 of the outer branch, bearing two short apical spines ; terminal 

 joint of the outer branch stoutly dilated at the base, distally 

 produced into a long, slightly pectinated spine and bearing 

 two stout marginal spines. 



Length 2*10 mm. 



Male. — Body rather shorter and more slender than that 

 of the female; cephalothorax rounded off behind, without 

 prominent angles; urosome slender, five-joitited, its second 

 joint produced ventrally into an acute papilliform process. 

 Right anterior antenna very tumid in the middle, its outer 

 margin in front of the swollen portion bearing four strong" 

 curved spines; the three terminal joints slender and of nearly 

 equal length, destitute of spines or marginal processes. Fifth 

 pair of feet very unequal in size ; outer branch of the right 

 foot much elongated and bearing a long, slender, terminal 

 claw; inner branch small, simple, biarticulate; foot of the 

 left side short and stout, its basal joint with a minute papilli- 

 form prolongation; distal joint bifurcate at the apex, foriiiino- 

 two unequal curved claws. L-riteral spines of the swimming- 

 feet finely spinulose in both sexes. 



Leng-th of the male 1"90 mm. 



