386 On Mochlonyx (Tipula) culiciformis, De Geer. 
this particular some specific difference prevails, the difference 
mentioned not being so great in Corethra pallida. 
The larve, on the contrary, are extremely different ; but it 
must also be pointed out that even within the genus Corethra 
there is no inconsiderable difference between the species, for 
according to Steger (dc. p. 556) the swimming-fans in the 
larve of his C. fusca do not consist of fringed sete (as in 
C. plumicornis), but of cleft setee (as in Mochlonyz). 
Mochlonyx culiciformis, De Geer. 
Tula culiciformis, De Geer, Mém. pour servir & Vhistoire des Insectes, 
tome vi. p. 372, pl. xxiil. figs. 3-12. 
Fusco-brunnea, ferrugineo-pilosa, thorace linea media dorsali 
duplici obscura notato, metanoto nigrescente, abdomine pallido, 
scutis dorsalibus maximam partem dense nigro-fusco irroratis. 
Palpi antenneeque nigro-fusca, antennis femine late, ant. 
maris anguste dilute balteatis, apice setarum cinerascentibus. 
Halteres pallidi, capitulo brunnescente. Pedes dilute flavi, 
genibus apiceque articulorum priorum tarsalium articulisque 
posterioribus vel posticis totis fuscescentibus. Ale maris 
fumatz, al. femine ante flavescentes. Long. 23-3". 
The indications of colour are drawn up from old dry speci- 
mens, as required for systematic analytical purposes ; from 
fresh individuals or spirit-specimens they would run as fol- 
lows :—The colour of the animal is dark brownish grey, but 
a broad band or spot on the anterior margins of segments two 
to seven of the abdomen above is chalky white. The under 
surface of the abdomen is milk-white anteriorly, but poste- 
riorly it becomes more and more brownish, with a small oval 
blackish-brown transverse spot on the anterior margins of 
segments three and four. The legs, especially on the under- 
side, are milk-white, but the upper surface of the femora and 
tibiee is somewhat brownish, as also the apices of the femora 
and tibiz ; the first and second tarsal joints, the greater part 
of the third, and the whole of the fourth and fifth joints, are 
still darker ; the last joint especially is remarkably dark. The 
antenne are milk-white, but the apex of each joint is broadly 
black. The palpi are blackish grey ; the halteres milk-white, 
with the knob brown. The underside of the head and pro- 
thorax are milk-white, as also the base of the wings, the rest 
of which are greyish, immaculate. The sete on the thorax 
are whitish grey or slightly yellowish; the long sete on the 
lateral margins of the abdomen pale greyish ; on the legs the 
setee are blackish grey or black, as also on the antenne, the 
dense tufts of which, however, have a brownish tint. 
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