22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. G8 



Tyye and 2 favatypes. — Higuito, San Mateo, Costa Rica (P. 

 Schild). Cat. No. 28456, U.S.N.M. 



A very slender species, with the habitus of an Anthomyzid, but 

 evidently an aberrant Melanomyza^ lacking the tibial bristle and 

 anterior pair of dorsocentral bristles. Possibly entitled to sub- 

 generic segregation. 



PSEUDOGRIPHONEURA (NEODECIA) MARMORATA, new species 



FeTnale. — Head black, densely gi'ay pruinescent, center of frons 

 faintly brownish, a spot between each antenna and eye and a narrow 

 cross band above mouth margin brown. Thorax concolorous with 

 head, with three broad dark brown dorsal vittae, the median one 

 extending over disk of scutellum, a brownish mark below humeral 

 angle and another along lower margin of mesopleura. Abdomen 

 densely gray pruinescent, with three large irregular dark brown 

 spots on anterior half of each tergite and quite large dots of same 

 <*olor at bases of the bristles along hind margins of tergites which 

 connect with the large anterior markings. Coxae and femora fus- 

 cous, trochanters paler, tibiae white, both extremities black; tarsi 

 white, apices of fore pair black. Wings yellowish, with a dark 

 cloud between apices of auxiliary and first veins and fainter clouds 

 on both cross veins. Halteres yellow. 



Frons flat, a little over one-third of the head width, and broader 

 than long; ocellar bristles strong; anterior orbital a little shorter 

 than posterior one; face almost vertical, flat; cheek narrow; third 

 antennal segment longer than wide, quite noticeably pilose ; arista 

 plumose. Thorax with two pairs of dorsocentrals and one pair of 

 strong prescutellar acrostichals. Inner cross vein a little before 

 middle of discal cell : last section of fourth vein nearly twice as long 

 am preceding one. 



Length, 3 mm. 



Tyj^e and six 'paratyj)es. — Higuito, San Mateo, Costa Rica (P. 

 Schild). Cat. No. 28475, U. S. N. M. 



The strikingly marked abdomen of this species, readily distin- 

 guishes it from cineracea Coquillett, the genotype and only recorded 

 species of the subgenus. The eyes in iivarmorata are not mucli nar- 

 rowed below as in cineracea^ and all the species in Pseudogrifho- 

 neiira, but it appears to me unneccessary to erect a subgenus for its 

 reception at this time. There are a number of species before me 

 from South America which agree with the above one in the bristling 

 of the thorax, a character they have in common with all the segre- 

 gates of Pseudogripho7ieura. 



