Vol.. \-III] ALDRICH— KELP-FLIES OF XORTH AMERICA 167 



cept behind the spiracle, several bristles below the latter ; calypters white, 

 the upper edge of the hind one projecting a little; lower part of sterno- 

 pleura with coarse, alntndant bristles. 



Abdomen tessellated, with rather distinct median black stripe ; first seg- 

 ment almost as long as the next two; a tifth segment visible dorsally as 

 a narrow edge before the hypop_vgium. Hypopj'gium of moderate size, the 

 first segment densely set with straight spiny bristles ; fifth sternite with a 

 long brown lobe each side of the excision. 



Legs entirely black ; front tibia with one seta in front, one or two slender 

 on hind side ; middle tibia with one on outer front, two on outer hind side ; 

 middle femur with the hind lower row becoming short and comblike near' 

 tip; hind tibia with three on hind (extensor), three on outer hind, four 

 on outer front side ; hind basitarsus with a conspicuous stout spine on 

 lower surface near base ; front and middle coxae very bristly ; pulvilli all 

 enlarged and elongated. 



Wing subhyaline; beginning at apex of auxiliary the costa bears seven 

 or eight stout setse, much larger than in the other species, diminishing 

 toward the end of the series (fig. 6). 



Length 6.8 to 7 mm. 



Female: Front wider, IJ/3 times as wide as one eye; width of parafacial 

 equal to length of third antennal joint; bncca fully half the eye-height; acr 

 rather distinctly four-rowed ; anterior tibia with one in front and two 



Fig. 5. Fuccllia costalis, costa. 



stout on outer hind side ; middle femur with only hairs in place of comb ; 

 mid tibia with one or two small on inner front side ; one large on outer 

 front, two or three irregularly placed on outer hind ; hind basitarsus as in 

 male ; pulvilli not enlarged. 

 Length 7 to 7.8 mm. 



Twenty-three specirtiens of both sexes ; two from Laguna, 

 Cal. (Cole) ; 20 from San Diego, Cal., June 29, 1917; and one 

 from Santa Barbara, Cal., July 6, 1917. 



The largest species of the genus. Cole (loc. cit.) says of it: 

 "This species is quite common on decaying kelp. Thev are 

 large, quick flies. They seem to be at least partially predaceous 

 in habit, as I have seen them pounce upon weakened sandhop- 

 pers and by their numbers soon overcome them." 



4. Fucellia pictipennis Beck. 



Becker, IMeddel. om Greenland, xxix. appendix. 411. — East 

 Greenland. 



Neilsen, ibid, xHii. 32, oc. in N. E. Greenland, lat. 76° 46'. 



Stein, Wien. Ent. Zeit.. xxix, 26, types redesc. — Hecla 

 Havn, East Greenland. 



Johnson, Psyche, xvii, 76, note. 



