48 COSTA RICAN DIPTERA 



Palpi yellow. 



Second antennal joint of male with distinct spine; fore femora of female 



with series of blunt spines on inner flexor margin spinicomis 



Without such characters hypoleuca 



Hydrellia tibialis Cresson 



1917. Hydrellia tibialis Cresson, Ent. NewS, xxviii, 341. 



This species is easily distinguished by the characters given in 

 the table of species. The Costa Rican specimens seem to be 

 identical with the type, although perhaps slightly more shining 

 and somewhat smaller. 



Represented by two specimens, collected over mud in Cartago, 

 Decehiber 12. 



Hydrellia calverti new species 



Black; extreme bases of tarsi pale; halteres lemon yellow. Wings hyaline. 

 Shining, metallic green. Frontal stripes opaque, black. Lunule and face 

 opaque, sericeous, ochreous to black. Pleura grajdsh. Femora brownish. 

 All tibiae silvery on outside. 



Face roundly carinated above, slightly swollen below; twice as long as broad, 

 with two to four bristles on each side. Mesonotal bristles strong; dorso- 

 centrals 1:1. Middle tibiae not enlarged. Second costal section slightly 

 longer than third. Length. — 1.5 mm. 



Type. — cf; Bonnefil Farm, Rio Surubres, Costa Rica, October 

 20, 1909, (sweeping at 800 ft. alt.), [Type No. 6120]. 

 .Hydrellia spinicornis new species PI. Ill, fig. 5. 



In general respects similar to hypoleuca Lw. 



Black; palpi, joints of femora and tibiae and bases of tarsi, pale. Halteres 

 yellowish white. Wings subhyaline, brownish with black veins. Opaque; 

 mesonotum, scutellum and abdomen somewhat shining. Dorsal surfaces 

 brownish pollinose. Face and lunule white; occiput below, pleura, venter, 

 femora, and tibiae light gray. 



Face flat or slightly convex below, with five to seven bristles on each side. 

 Antennae of male with second joint distinctly produced at angle and furnished 

 with distinct spine. Dorso-centrals arranged 0: 1, near sutm-e. Fore femora 

 of female with series of minute, blunt spines on apical portion of inner flexor 

 margin. Length. — 2.25 mm. 



Type. — cf ; Alajuela, Costa Rica, September 15, 1909, (sweep- 

 ings at 3100 ft. alt.), [Type No. 6121]. Paratypes.—l d" , I 9 ; 

 topotypical. 



Another female, along ditch at Cartago, May 17, also belongs 

 here. 



