LTMNOBTA. 281 



tioned as three in number in all the species. The larvge of most 

 species live in the earth or in fungi^ but that of L. replicata is 

 aquatic, and its body is furnished with numerous long filamentous 

 processes which appear to be internally supplied with air-tubes. 

 It is furnished with anal claws, which in conjunction with its an- 

 nular tension and relaxation, and the hooks of its mouth, assist it 

 in walking over the aquatic plants. It can withdraw its head so 

 completely that the anterior margin of the first segment of the 

 body closes the orifice. The pupa has dorsal hooks on the three 

 or four terminal abdominal segmoits. Tlie species may be arranged 

 in the following groups : — 



a. Wings with a discal areolet. 



h. First externo-meclial vein forked. Radial vein forked. 



c. Fork of the first externo-medial vein with a petiole between it 

 and the discal areolet. 



d. Two veiulets between the siibanal vein and the third externo- 

 medial.— Meig. Z\v. i. 121. Div. C. pi. 4. f. 16. Tdioptern, 

 Mcq. Species 1-3. 

 d d. One veialet between the subanal vein and the third externo- 

 medial. 



e. Radial vein united by a vcialet to the subcostal at its fork. 

 — Meig. Zw. i. 125. Div. E. pi. G. f. 2. Limnophlla p., 

 Mcq. Species 4. 

 e e. Radial vein united to the subcostal at some distance be- 

 yond its fork. 

 /. Petiole of the first externo-medial vein a little shorter 



than its fork. — Llmnophila p., Mcq. Species 5, 6. 

 ff. Petiole of the first externo-medial vein as long as its 

 fork.— Meig. Zw. i. 127. Div. G. pi. 4. f. 20. Limno- 

 pjula p., Mcq. Species 7-12. 

 ///. Petiole of the first externo-medial vein longer than 

 its fork. 



ff. Petiole of the first externo-medial not twice the length 

 of its fork.— Meig. Zw. i. 122. Div. D. pi. 4. f. 1.5. 

 Limnopldla p., Mcq. Species 13-15. 

 ff ff. Petiole of the first externo-medial vein twice the 

 length of its fork. — Limnopldla p., Mcq. Spe- 

 cies If). 

 ff ff ff. Petiole of the first externo-medial vein more than 

 twice the length of its fork. — LimuopU'da p., Me(j. 

 Species 17. 

 ff ff ff ff. Petiole of the first externo-medial vein about 

 six times the length of its fork. — Meig. Zw. i. 120. 

 Div. F. pi. 6. f. 3. — Limnopldla p., Mcq. Spe- 

 cies 18. 



VOL. IV. 2 o 



