FAM. EMPIDIDJE 87 
the Microphorus group it follows that the perpendicular crossvein has been independently developed in 
Parathalassius. "The species of the genus frequent the sands of the seashore, which habit accounts for 
their white bristles and silvery gray color. 
Geographical distribution. 
1. P. Aldrichi, Melander, Ent. News, Philad. Vol. 17, p. 374, fig. (1906). California, Washington. 
2. P. Blasigii, Mik, Wien. Ent. Zeit. Vol. 10, p. 217 (1891); Becker, ibidem, S. Europe; N. Africa. 
Vol. 28, p. 29 (1909). 
alter, Becker, Zeitschr. Hym. Dipt. Vol. 7, p. 119 [1907] (Sehtistostoma). 
3. P. candidatus, Melander, Ent. News, Philad. Vol. 17, p. 375 (1906). Washington. 
4. P. Melanderi, Cole, Report Laguna Marine Labor. Vol. 1, p. 154,f. 88(1912). California. 
2. GENUS MICROPHORELLA, BECKER 
Microphorella, Becker, Wien. Ent. Zeit. Vol. 28, p. 28 (1909). 
Characters. — Small opaque black bristly species with the eyes separated in both sexes and 
with the anal angle of the wing reduced, the legs and halteres always black. Front broad in both male 
and female, with a pair of converging strong fronto-orbital bristles, ocellar triangle not elevated, the 
ocelli widely spaced apart, ocellar bristles strong and distant from each other; face long, with parallel 
sides, narrower than the front, no cheeks; eyes with microscopic pubescence, the lower facets of the male 
very slightly larger than the upper; antenne inserted above the middle of the head, two-jointed as the 
basal joints are fused. the basal joint without bristles, the outer joint conical, pyriform or cylindrical, 
pubescent, with a rather thick, two-jointed apical arista, which is geniculate beyond the minute basal 
joint; mouthparts very short, not protruding, fleshy, palpi small, elongate oval and tipped with a single 
hair; occiput hairy the upper part setose and with stronger vertical bristles. "Thorax large, robust, 
longer than the abdomen, with a complete series of about six strong dorsocentrals, acrostichals biseriate 
and biseriate setulze present between the dorsocentral and supraalar bristles, one strong posthumeral, 
one notopleural, two scutellar bristles; pleure bare, but opaque pollinose. Abdomen thick, its hairs 
sparse and very short; pygidium enormously enlarged, sometimes as large as the remainder of the abdo- 
men, twisted to the right, globular, completely enclosed above, the fourth ventral more or less excised 
medially along its hind margin ; no ovipositor, the last segments of the female abdomen short and broad 
and margined with bristles. Legs slender, in the male often deformed, especially the tarsi, middle tibize 
with a short apical spur, hind femora more or less ciliate below. — Wings rather pointed, broadest at the 
middle, the hind angle greatly reduced and not rectangular, costa encompassing the entire wing, its 
basal bristle strong, no stigma, auxiliary vein distinct, usually shortened, first vein ending beyond the 
middle of the wing, third vein simple, discal cell narrow, its basal crossvein weakened, the posterior 
crossvein very oblique, basal cells minute, anal crossvein round, anal vein present or absent, no alula 
and almost no alular hairs; fringe of the calypteres weak. 
Type species : M. ?rzcox Loew, apparently a very rare form and the only species known to 
Becker. The American species are closely related to each other but are easily recognized by the pecu- 
liar secondary sexual characters of the males. "They occur in the grass and bushes along streams. 
Becker proposed Microphorella as a subgenus of Microphorus. | As shown in the table of genera the genus 
is much more closely related to Parathalassius, but is distinct from both, and is well entitled to generic 
rank. 
