184 PSYCHE [Oct.— Dec. 



DESCRIPTIONS OF THREE NEW DIPTERA OF THE GENUS 



PHTHIRIA. 



BY CHARLES W. JOHNSON, BOSTON, MASS. 



Phthiria cyanoceps, sp. nov. 



$ Front, face, and occiput light bluish gray, ocellar triangle black ; first and second 

 joints of the antennae light yellow, third joint black, and about twice the length of the first 

 and second joints combined; proboscis black, nearly double the length of the head. Thorax 

 bluish gray (becoming blackish when dampened) ; scutellum light yellow. First and second 

 segments of the abdomen black, with a sharply defined, narrow, posterior margin of yellow 

 •on the first segment ; posterior margin of the second and all of the remaining segments, 

 widely margined with grayish white, leaving a narrow, blackish, basal band, the segments 

 are often so contrasted in dried specimens that the dark anterior portion is more or less 

 concealed. Halteres white. Legs light yellow, tip of the metatarsi and all the other joints 

 of the tarsi black. Wings whitish hyaline. 



$ Front and vertex broad, yellowish, occiput more prominent than in the male ; ocelli, 

 a small spot above the base of the antennae, and a short line on the occiput extending toward 

 the cervix, on each side of a tnedian depression, black, the first abdominal segment black, 

 the others brownish, and all widely margined posteriorl\- with _\ellow. Length, 1.5 mm. 



Four males and one female were collected by Mr. Owen Bryant and myself, 

 on September 8th, by sweeping over the scanty vegetation on a white sandy tract 

 near the beach at Cohasset, Mass. The eyes are a brilliant blue when living, 

 changing to purple after death, and to dark brown when dry. It is the smallest of 

 our described species. Types in the New England collection of the Boston society 

 of natural history. 



Phthiria aldrichi, sp. nov. 



$ Face, ocellar triangle, and occiput grajj'ish white, frontal triangle yellowish ; face 

 and occiput bearing conspicuous white pile; first and second joints of the antennae yellow, 

 third black and about double the length of the other two; proboscis black and more than 

 twice the length of the head. Thorax grayish white, sparsely covered with whitish hairs 

 {in damp or greasy specimens the thorax is black) ; scutellum, postalar processes, and a spot 

 between the base of the wing and halteres yellow. Abdominal segments blackish widely 

 margined posteriorly with yellow, the black being most prominent on the second segment, 

 -genitalia and venter yellow. Legs variable in color, usually brownish black, with the base 

 and tip of the femora and the base of the tibiae and metatarsi more or less yellowish. Hal- 

 teres white, wings whitish hyaline. 



$ Front and face yellow, cellar triangle and a short line on the occiput, on each side of 

 ■the median depi'ession, black. Humeri, lateral margins, upper portion of the pleurae, postalar 



