70 TJniversity of California Publications. [Zoology 



segment half as long- as middle one. Fnrcal blades five or six 

 times as long as broad. Anterior antennae reaching beyond end 

 of furea by about the last joint. Fifth feet 4-jointed, last joint 

 with three apical bristles, all of which are plumose ; the basal 

 joint with a tuft of long hairs (PI. 13, fig. 79). 



Male : Similar to female, but head not as broad, and furca 

 not entirely symmetrical (PI. 11, fig. 41). Abdomen 5-jointed^ 

 anal and genital segments of equal lengths ; the third segment is 

 the longest of the five. Grasping antenna on the left side, reach- 

 ing back to end of furca. First joint of fifth foot on right side 

 (PI. 14, fig. 97) with a long spine. 



Length : Female, 8-8.5 mm. Male, 7-8 mm. 



Coloration : Very translucent and without pigment. 



Occurrence : Two males were taken with five females which 

 are undoubtedly M. piinccijs. Coll. 1030. 



Metridia atra n. sp. 



PI. 9, figs. 15, 1(5; pi. 11, figs. 39, 40; pi. 13, fig. 78; pi. 14, fig. 9.5. 



Front of head produced into a rather prominent process, ros- 

 tral filaments long, slender, and plumose (PI. 9, fig. 15). The 

 sides of the last thoracic segment end in a strong point; furca 

 symmetrical in both sexes, each blade as broad as long (PI. 11,. 

 fig. 39). The anal segment has on each side a bluntly conical 

 projection which reaches back about to the base of the outer mar- 

 ginal furcal bristle (PL 11, figs. 39, 40). The furca has a blunt 

 process between the two outer terminal bristles (PI. 11, fig. 39). 

 The inner marginal or dorsal furcal bristle is extremely slender 

 as compared with the others. The anterior antennae of the fe- 

 male are 23-jointed and reach beyond the furca; grasping an- 

 tenna on right side. Right fifth foot of male longer than the left ; 

 second and third joints of outer ramus of right foot v.-ith spines 

 on inner border, second joint of outer ramus of left with a heavy 

 process extending along outer border (PI. 14, fig. 95). Fifth foot, 

 of female 4-jointed, the last joint with three apical bristles, the 

 innermost not plumose (PI. 13, fig. 78). 



Length : Female, 11.5-12 mm. Male, 9 mm. 



Coloration : Both sexes are alike ; black pigment in cephalo- 

 thorax except the most anterior portion of the head ; it is absent 



