PEOCEEDINGS OF THE NATIONAL MUSEUM. 



597 



more sluggish tlinii Ganimarus, being wont to lie curled up on the sur- 

 face of the water. In color they were translucent pearly white; around 

 the bases of the legs of the pereiou were fantastically branched stellate 



Fi5:.4. 

 HVBLl.s SERRATA, Female 



pigment cells of a rich purplish brown color. The mass of eggs in the 

 brood pouch appeared like a claret-red globe. The four eyes were usu- 

 ally bright red, with considerable pigment around their sloping sides. 



In a few individuals the eyes were 

 black, and in alcoholic specimens the red 

 eyes turn black. 



Male. — In looking over several hun- 

 dred specimens of Byhlis serrata, now 

 and then I came across one that had 

 <lied in a straight condition, instead of 

 being more or less curled up like the 

 others. The straight ones possessed no 

 incubatory pouch, were smaller, and ha<l 

 very long inferior anteunte: they were 



apparently the males of Bt/hlis .serrata, for they had serrated coxne 

 (Fig. 5).' The differences are those usually characteristic of the sexes 

 in this genus.- 



The anteunne especially are the organs which exhibit sexual dimor- 

 phism in the family Ampeliscida'. 



BVBLis SEKKATA, Female. 



First coxa showing si^rratiou of ventral inarfjii 



' For resemblances autl diflereuces compare tigs. 1 and ti. 



'See the table of sexual differences iu liijhJis gaimardi, a typical species of the 

 geiuis, p. 601. 



