Vol. VIII] 



ALDRICH— KELP-FLIES OF NORTH AMERICA 



169 



This Paciiic species is very closely similar to maritima of the Atlantic 

 coast ; it is easily separated in the male sex, but pretty close attention is 

 required to distinguish the females, except by the locality labels. 



Alale : Compared with maritima, the male of nifitibia has black or 

 blackish palpi instead of yellow ; the bucca is more than half the eye- 

 height ; the hind femur has no protuberance on the under inner side at 

 base; the middle femur has a long bristle below at middle and one nearer 

 base, whereas there is none in tiuiritinia; the second, third and fourth 

 abdominal segments are shortened (retracted) so much that they are 

 together usually not much longer than the first segment ; and the hypopyg- 

 ium is very much larger and more globose. Among these characters, the 



Fig. 6. Fuceltia rufitibia, front view of head in female. 



color of the palpi and the absence of the hind femoral tubercle are ample 

 to distinguish the species. The forceps are difficult to draw out, but are 

 found to be very slender and nearly straight, shining black, more like 

 needles than hooks. 



Female : This sex is distinguished from maritima by the palpi, bucca and 

 middle femur, being as in the male ; the setules of the costa are longer than 

 in the Atlantic species, and this is also true in the male. 



Length 3 to 4 mm., noticeably less than in maritima. 



Forty-five specimens, both sexes; Pacific Grove, Santa Bar- 

 bara, Lagfiina, Santa Monica, Lono" Beach and San Dieeo, Cal. ; 



