AQUATIC INSEcrrS IN NEW YORK STATE 447 



Diamesa waltlii Meigen 



7 Antennae of the female. x50 



8 Dorsal aspect of the male genitalia. x50 



9 Wing of tJie female. C Costa. 8c Subcosta. R Radius. M Media. 



Cu Cubitus 



10 Male genitalia, ventral aspect. xoO 



11 Fore foot of the female 



PLATE 48 



Dlxa m^odesta n. sp. 



1 Ventral surface of larval head. x50. I Labrum. a Antenna, mx Max- 



illa with its palpus 



2 Mandible of the larva. xl90 



3 Maxilla and its palpus, p. xll5 



4 rupa. xl5 



5 Larva, ventral view. xl5. a \ eutral caudal lobe, b Ventral foot 



bristles, c Abdominal prolegs 



Dorsal view of the dorsal head sclerite. x60 



7 Dorsal view of the caudal appendages of the larva. x40. p " Tri- 



angular chitinized plate." s Spiracles 



8 Wing of the imago. xl5. 8c Subcosta. R Radius. M Media. Cu 



Cubitus. A Anal 



Diamesa waltlii Meigen 



9 Ventral view of the labrum of the larva. xl90. ; Jointed appendages, 



e Epipharynx 



10 Ventral view of the labium of the lai'va. xl90 



11 Larval antenna. xl90 



12 Larval mandible. xl90 



13 Pupa. xl2 



PLiATE 49 



Chironomus sp. 



1 Hypopharynx of the larva. xllO 



2 Antenna of the larva. xl90 



3 Ventral aspect of the upper lip, showing the epipharynx. xllO 



4 Head and thorax of larva, showing the thoracic proleg. xl5 



5 Ventral aspect of the head, mn Mandible, tnx Maxillae. I Labium. 



x50 

 G Mandible. xllO 



7 Caudal end of larva, with its anal prolegs. xl5 



8 Frontal aspect of the larval head. x50. //■ Labrum. m Mandible. 



a Antenna. I Labium 



9 Dorsal aspect of the larval maxilla. xl90 



10 Ventral aspect of seventh, eighth and ninth abdominal segments of 



pupa 



11 Genitalia of the male. xoO 



12 Pupa 



PLATE 50 



Thalassomyia obscura u. sp. 



1 Antenna of the larva. xl90 



2 Ventral aspect of the larval mandible. xl90 



3 Ventral aspect of the upper lip (labrum). xl90, e Epipharynx 



