BRITISH FLIES 



35 



III, — Remarks and Illustrations. 



With tlie aid of tlie above table of Brauer, and the following illustrations and 

 remarks, the student should be able to decide on the family of any British Brachy- 

 cerous larva he may have before him. 



Fig. 54.— Head of 

 Stratiomys larva. 



Suborder: Orthorrhapha Brachycera, 



Fam. Stratiomyiid.e. Larvi^ of eleven very distinct segments and head, this 

 narrow, hemicephalous (fig. 54), usually with an eye- 

 like prominence on each side ; no pseudopods : ter- 

 minal spiracles not visible, being placed entirely inside 

 a chamber, the orifice of which is usually closed or 

 obscure. Habits iKpiatic or in seiniliquid matter. 

 Pupa coarctate. (This is not the case in any other 

 family of Orthorrhapha Brachycera.) The larvte 

 of this important family though very easily recog- 

 nised exhibit considerable variety. 



1, Stratiomyincc. In this subfamily the last seg- 

 ment is more or less elongate and narrow (fig. 55), 

 and the lips of the terminal breathing chamber are 

 fringed with fine hairs. The larva is peripneustic. Stratiomys and 

 Odontomyia are very frequently met with ; and according to 

 Haliday the larva of Orycera is similar, though the genus is usually 

 placed in Clitellariince. 



2. Clitellarnnce. Neviotelus of this subfamily has been described 



by Haliday. It has, in addition to 

 the head and eleven segments, a ter- 

 minal lip visible from the upper side 

 of the body, and this lip bears only 

 a few bristles (fig. 56), not a fringe 

 of hairs. The cleft giving entrance to 

 the breathing chamber is transversely „ ^'°- ^^•— 



1 , •' stratiomys furcata 



eionoate. ^ ^ larva, natoral size. 



3, Sargmce. Various descriptions 

 and several figures have been published of larvje 

 supposed to be Saryus or its allies ; but they are 

 either bad or the identification is 

 doubtful. The larva in the Sar- 

 Fio.5Q.-h3^y-^andi^stjegmMom -.^^^^ -^ probably very like that 



above of Nemotclus migtnosus. ^' „ ,^ •', , ■'„, •' , . , . . 



[After Haliday ot JS emoteius. lue slit giving 



entrance to the In-eathing chamber 

 may or may not be visible from above, the accounts being- 

 unsatisfactory and to some extent contradictory. 



4. Berime. The larva of (Jhorisops tibialis 

 has been imperfectly described and figured. 

 It appears to be generally similar to Kemo- 

 teliis, but the cleft of the breathing chamber 

 is not visible from above (fig. 57). 



5. Fachyyastrince. Orifice of the respira- 

 tory chamber very small, opening on the 

 upper surface of the terminal segment a little 

 before the extremity : the portion of the 

 segment behind this orifice marked off by a 

 more or less short and indistinct suture 

 (fig. 58). 



6. Xylomyiiiice. Orifice of the respiratory chamber forming 

 the posterior extremity of the body, looking backwards and 

 furnished with well-marked lips. Larva amphipneustic (fig. 59). 



Fam. Acanthomerid,-e. This family does not occur in o^wj(atl^upa!"'^x'io! 

 Europe. The larva has been imperfectly described by Brauer, 

 and more recently by Karl Fiebrig. It is peculiar : thick-skinned, with small 

 head, and large prothoracic segment : retuse behind, and the spiracles concealed 



Fig. 57. — Last two 

 segments of Ckorisops 

 tibialis. 

 [After Handlirscli 



