274 DIPTERA FROM SOUTHWESTERN UNITED STATES 



latter elongate, third joint more than twice as long as second; 

 arista bare, much thickened on basal half; presutural acrostichals 

 two-rowed; postsutural dorso-centrals four; sternopleurals 1:2; 

 apical abdominal segment in female with four short, stout, cuj'ved 

 thorns; third vein bare at base. 



Tetramerinx calif orniensis sp. n. 



Female. — Black, slightly shining, densely gray pruinescent. Head black, 

 opaque, frons, face, orbits, and cheeks with dense, slightly brassy pruinescence; 

 antennae, proboscis and palpi black. Thorax with three narrow brown 

 vittae, one along bases of acrostichals, the others along bases of dorso-centrals, 

 the larger bristles on dorsum each set in a brown dot. Abdomen with an in- 

 terrupted dorso-central brown line, a similarly colored spot on each side of 

 dorsum of segments two and three, and a brown dot surrounding base of each 

 bristle. Legs black, all of tibiae and apices of femora ferruginous. Wings 

 clear, veins brown. Calyptra white. Hal teres yellowish. 



Each orbit with four strong bristles and a number of setulose hairs, the 

 latter most numerous anteriorly laterad of the bristles; cheek about twice as 

 high as width of parafacial in profile. Mid tibia with two posterior bristles; 

 hind femur with two strong bristles on antero-ventral surface near apex; hind 

 tibia with one antero-ventral, one postero-dorsal, and two antero-dorsal 

 bristles. Venation similar to that of iinica Stein. Length, 4.5 mm. 



Type.— 9 ; San Francisco, CaUfornia, May 27, 1908, (F. E. 

 Blaisdell), [A. N. S. No. 6198]. 



The only other described species which belongs to the genus is 

 unica Stein, which has the abdomen with central stripe only, and 

 the legs black. The species I described as Tetramerinx brevicornis 

 does not belong to this genus but to one of the segregates of 

 Limnophora. 



LIMNOPHORA R.-D. 



There are several species of this genus in the collection, all the 

 specimens being females. 

 Limnophora narona Walker 

 1849. Anlhomyia /iarona Walker, List, iv, 945. 



This species is distinguished from all others known to me from 

 North America, except discreta Stein, by the convergence of the 

 third and fouith veins at their apices, and the presence of bristles 

 on base of third vein and on the plate on venter of prothorax be- 

 tween the fore coxae. These characters in my opinion justify 

 the generic separation of the species possessmg them from the 



