ON ANTHURA GRACILIS (MONTAGU). 



241 



of varying lengths, and three long sensory filaments. In the male the 

 long flagellum reaches to the posterior margin of the second peraeon-seg- 

 ment, and consists of twenty joints in the Eddystone specimen (Fig. 1), 

 the first joint short, the second constricted proximally and expanded 

 distally. All the joints except the first are fringed with very long, 

 delicate, outstanding setae, giving a brush-like effect to the antenna. 

 The smaller male from Drake's Island had sixteen joints in the flagellum. 

 Loiver Antennae. The second joint of the peduncle is greatly expanded 

 distally ; the third very small ; fourth rather longer ; the fifth equal in 

 length to the third ; flagellum in the female four-jointed, the terminal 

 joint furnished with a thick cluster of long setae. The flagellum in the 

 male is six-jointed, the first joint as long as the others taken together. 



Anthnrn gracilis. Fic. 0. — Abnormal maxillipeds, o, Drake's Island specimen, x 75. 

 Fic. 7. — IMaxilliped, o, Eddystone specimen, x 75. 

 P'ic. 8. — Ma\illiped, 5, 10.5 mm., X 75. 



Mouth organs as described by Norman and Stebbing. They are larger 

 in the female than in the male. The mandibles have a three- jointed 

 palp ; the falcate process terminates in three blunt teeth, the thin blade 

 below with five serrations, the serrations more acute in the males ex- 

 amined than in the females. 



Maxillipeds. Palp one-jointed (Figs. 7 and 8) tipped with a row of 

 four stiff slightly curved setae. In Fig. 6 the maxillipeds of another 

 male are figured, showing an abnormality in that a second and very 

 distinct joint is developed. The specimen was perfectly normal in all 

 other particulars, but it serves to illustrate the danger of describing 

 species from one or two solitary specimens. 



Gnathopod 1. In the male the first and second joints are subequal, 

 both produced distally on the upper side over the succeeding joint ; 

 third joint produced on the under side. The fifth joint or hand narrowly 

 pyriform, widest proximally, tapering to the insertion of the finger,, 

 rounded above, and turned at a different angle to the rest of the appen- 



