516 MODERN CLASSIFICATION OF INSECTS. 
what like that of the gnat, but it is straight, and the thoracic appen- 
dages are pointed. Goring and Pritchard have figured this larva (my 
Jig. 124. 12.) and pupa (fig. 124. 13.), but have unfortunately omit- 
ted the imago. (Nat. Hist. Obj. Microsc. pl. 2.) These authors assert 
that the larva does not shed its skin on becoming a pupa, and have 
made some other erroneous statements, such as confounding the sexes 
of the perfect insect, &c. Slabber (Matuurk. Verlustig. p. 17. pl. 3, 4.) 
and Lyonnet (Mém. Posth. pl. 7. fig. 3, 4. 8. 14. 18., &c.) have also 
figured the transformations of a Corethra similar to those of Réaumur. 
Lyonnet has further noticed that the eggs are arranged in great order, 
being on a kind of convex disc; they are, however, laid on their 
sides, and arranged in circles. 
The larva of Tanypus maculatus Mezg. (according to Latreille, 
Gen. Crus. tom. iv. p. 248.), figured by De Geer (tom. vi. pl. 24. 
fig. 15—19.), resembles Réaumur’s figure of the larva of Corethra, 
except in being less elongated, with a more oval head, the thorax 
having at its base beneath a long pediform bifid tentacle, and 
the extremity of the body is terminated by four minute triangular 
plates, with two long pediform appendages beneath and two slenderer 
ones above, with long terminal hairs. The pupa is like that of Culex, 
and bent, but with broader oval thoracic appendages, and the anal 
plates small. Macquart (Hist. Nat. Dipt. tom. i. p. 43.) has described 
some larvae closely resembling the last, which he also regards as those 
of a species of Tanypus. Lyonnet has figured the transformations of 
another species of Tanypus (Mém. Posth. pl. 17. fig. 1, 2.5, 6. 17., 
&c.), the larva of which forms for itself a movable case of silk 
and moss spun together. Fries has also observed the transformations 
of Tanypus varius; the eggs of which are deposited by the female 
on the leaves of aquatic plants, and covered with a mass of gluten. 
The larvee and pupe do not differ from those figured by De Geer. 
The larve of Chironomus plumosus (figured by Réaumur, tom. iv. pl. 
14. fig. 11, 12., and tom.v. pl. 5., and my fig. 124.14.) are very vermiform, 
and of a blood colour, whence they are named blood-worms ; they are 
found in stagnant water, and are very active, twisting about in all 
directions. The head has two ocelli-like points, and two biarticulate 
palpi, observed by Macquart; beneath the first thoracic segment are 
two short pediform tentacles ; the extremity of the body has also two 
still larger, and four small oval appendages ; each of the two preceding 
joints is furnished with a pair of long fleshy filaments. These larvee as- 
