202 DOLTCHOPID^.. 



sus is compressed and dilated at the tip, nearly as long as the following 

 joints together. 



Not common about ponds. (E. S. I.) 



15. crassipes, Mg. zw. iv. 50. 10(1824); Mq.; Ztt. ; Lw. Ob- 

 scure aneiim, hi/j)ostomate arr/enteo, pedibus anticis flavis, feuionim basi 

 nigra, metatarso apice dilatato, intermediis flavis, articulis tarsi duobus 

 idtimis dilatatis atris, posticis ni(/ris femore mutico, hypopygii appendici- 

 bus externis elongatis/«rcrt7!is, 3Ias. Long. 2^; alar. 5 lin. 



Male. Dark brassy. Face silvery -white. Antennfe shorter than the 

 arista. Wings smoky-hyaline, dilated in the middle, the hind edge 

 sinuated, subapical vein strongly curved rather beyond the middle. 

 Outer appendages of the hypopyrjium very long, slender, dingy yellow, 

 forked about the middle, with the upper branch short ; inner appen- 

 dages slendei", curved, setaceous, pale. Anterior leys yellow ; the fore 

 femora, sometimes also the middle pair, blackish at the base ; fore tibiae 

 with very slight and few spines ; fore tarsus shorter than the tibia, the 

 first joint longer than the rest together, compressed and dilated at the 

 tip, the exterior joints dusky ; middle tarsi with the last ttvo joints di- 

 lated, deep black, the last one oval. Hind leys long and stout, black ; 

 femora unarmed, sometimes yellowish at the base ; the tibiae with very 

 few and slight spines. The female is described as having the femora 

 yellow, the base of the fore and the tip of the hind pair usually blackish ; 

 ditfering from some nearly allied ones (as of species 16) by the longer 

 hind legs. 



Rare. (E. I.) 



16. commune, Mg. ! zw. iv. 52. 13 (1834). — spinicoxum, Lw. Ob- 

 scure viridi-aneum, femorihus posticis muticis ; Mas. capite pedibusque 

 nigris, tibiis ferruginosis, posticis basi et apice nigris, anticis crebro bi- 

 pectinatis, metatarso antico longissimo apice hirto, appendicibus externis 

 hypopygii furcatis ; Fosm. femoribus tibiisque flavidis, femoribus ante- 

 rioribus basi subtus, posticis apice supra fuscis. Long. 2^ ; alar. 5 lin. 



Bark brassy-green, not shining. Face and beard black in the male ; 

 in the female the face yellowish-grey, and the front glossed with the 

 same. Arista nearly half as long again as the antennas in male, thi'ee 

 time as long in the female. Wings brownish-hyaline, darker in female. 

 Alulae fringed with black in male. Inner appendages of hypopygiura 

 rather slender, parallel, at the tip pointed and hooked, at the base en- 

 larged into a tooth ; outer ones one-half longer, gradually dilated from 

 the base, forked before the middle, the upper branch about one-third 

 the length of the lower. Legs of the male black, the coxa} and femora 

 (the fore pair behind, the others beneath) clothed with black hair, hind 

 femora unarmed, the middle coxae with a short black spur ; anterior 

 tibiae brownish, the fore ])air strongly and rather thickly bipectinated, 

 the hind tibiae dingy yellow, with the base and ti]) blackisli ; anterior 

 tarsi brownish at the base, the/o;'<? metatarsus longer than the following 



