DlVTERA. 347 



inferiorly, and bearing tjie antennae above. The latter are inserted 

 in the front, as usual. 



Stratiomys, Fab.^ 



Or Stratiomys, properly so called, where the antennae are much 

 longer than the head, the first and last joint being greatly elongated; 

 the latter is fusiform, or resembles a narrow and elongated club, nar- 

 rowed at both ends, consisting of at least five distinct rings *, with- 

 out an abrupt stilet at the extremity. The two rings that compose 

 it are not distinguished from the others by any sudden contraction. 



The body of the larvae is long, flattened, invested by a coriaceous 

 or firm skin, and divided into annuli, of which the three last form a 

 tail terminated by numerous plumous hairs which radiate from the 

 extremity. The head is squamous, small, oblong, and furnished 

 with a great number of little hooks and appendages with which 

 they agitate the water that constitutes their doVnicil. They respire 

 by keeping their tail on the surface of the water, an orifice situated 

 between the hairs at its extremity affording a passage to the air. 

 Their skin becomes the cocoon of the pupa. They do not change 

 their form, but become rigid, and incapable of moving or bending 

 their body; their tail is frequently at an angle with the trunk, and 

 thus they float upon the water. The pupa only occupies one of the 

 extremities of its cocoon, and the perfect Insect issues from it through 

 a fissure which is effected in its second ring, and remains on its ex- 

 \iviae, where its body becomes firm, and its development is com- 

 pleted. 



A common species in France is the 



S. chamcEleon, Fab. ; Roes., Insect. II, Muse. v. Six lines in 

 length; black; extremity of the scutellum yellow, and armed 

 with two spines; three lemon-coloured spots on each side of 

 the superior part of the abdomen f. 



Odontomyia, Meig., 

 Where the antennae are hardly longer than the head, with the two 

 first joints short, and almost equal in length ; the third forms a highly 

 elongated slender cone, composed of at least five distinct rings, the 

 last conical, abruptly compressed and curved inwards, represents the 

 extremity of the stilet ; otherwise similar to the others %• 



Ephippium, Lat. — Clitellaria, Meig., 

 Where also the antennae are hardly longer than the head, and the two 

 first joints short, but the third forms a shorter and thicker cone, with 

 the fourth ring conical, truncated, abruptly attenuated at the extre- 

 mity, and terminated by a stilet of two joints, the last of which is 

 much the longest and slightly arcuated. 



E. vulgaris ; Stratiomys ephippium, Fab. ; Schoefi^., Monog., 



* There are six of these rings, as in the following Insects, but the fifth is very 

 short and indistinct. The two last are converted into a stilet or a seta. 

 f For the other species, see Latreillc, Meig«n, and Macquart. 

 X Idem. M. Meigen now unites this genus with the preceding one. 



A A 2 



