240 [October, 



iiTOf^ularly qiiadriseri.al, the outer pairs stronger than tlie inner pairs 

 and the thorax devoid of any pubescence between these outer rows 

 and the dorsocentrals. Abdomen all dark when viewed in some 

 lights from above, but when the light comes from behind the insect 

 and the abdomen is viewed right from behind, the usual somewhat 

 triangular, narrowly separated dark patches are plainly visible on 

 the 2nd-4th segments — largest on the second and very small on the 

 4th segment ; first segment nearly all darkened. Legs slender and 

 very sparsely bristled ; front tibiae bare behind ; middle tibiae with 

 one small bristle behind ; hind tibiae with one small anteroventral 

 and one small anterodorsal bristle a little above it ; only one small 

 preapical bristle; hind femora with 2-3 anteroventral bristles 

 towards tip. Wings faintly brownish and rather pointed, radial 

 A-eiu long, ending in costa practically equidistant from wing-tip 

 witli the discal. Squamae usually brownish. Halteres yellow. 



2 . Head iu prohle with eyes not so large as in male, but similar 

 in outline. Interfi'outalia produced forwards almost to front of 

 frons. Thorax dark greyish with three faint brownish stripes down 

 the lines of bristles. Abdomen similar to thorax in colour, the faint 

 brownish patches as large as in male. Bristles of legs as in male. 

 Wings clearer and not quite so pointed. Squamae paler. 



Length 4-4'6 mm. 

 , This species is not at all uncommon and is one which hibernates in 

 houses, numerous females with a few males may often be found on 

 windows in the late autumn. In the open the species is more 

 usually found during August. 



It has not previously been associated with L. polystigma in the 

 subgenus Gymnodia, but it agrees so remarkably in many characters 

 with that species that it must surely belong to the same group. 

 Dr. Eltringham bred this fly from horse-manure in the course of 

 some experiments on the House-fly in relation to the farm manure- 

 heap (Journ. Agric. Sc. vii. 1916, p. 452). A heap was made on 

 August 24th of horse-manure from a stud stable, and on August 30th 

 this was completely enclosed with a tent-like cover of cheese-cloth. 

 By September 10th 37 specimens of Z. htonilis and 12 Mtisca doniestica 

 had appeared from the heap. L. humilis has previously been known 

 under the name of scptemnotata, but Eingdahl has found that the 

 true septemnotata of Zett. is quite a different species. 



Sulgenus Neolimnophoea. 



1 (2) Presutural acrostichals tri- to quadri-serial and without distinct 

 stronger pairs. A narrow black frontalia obvious iu both sexes (iu 

 5 divided by the iutertVoutalia). Abdominal dark patches faiut, 

 but distinctly visible in c^ when viewed from behind 

 .... 1*J. maritivia v. liod 

 candicans Villen. 

 S. A grey species, but never so silvery-grey as, and always 

 slightly larger than, viryo. Head rather longer (especially on the 

 lower part) iu proportion to depth. A distinct " keel " between the 



