88 NEW YORK STATE MUSEUM 



lih Full-grown larva over 6mm. in length; mandible not 

 transversely wrinkled 

 i Labium with its teeth rounded, pl.20, fig.9 



35. D i a m e s a waltUi.' 

 a Labium with its middle tooth broadly truncate 



37. T h a 1 a s s o m y i a f u s c a 

 Note. — See addenda for .several anomalous species. 



Pupae 

 a Pupa floats nearly motionless in a vertical position at the surface of the 



water, pi. 17, fig.ll. {Group C e.r at o p o g on) 



aa Pupa not as above 



h Active pupa swimming with a jerking motion in the water like a culex 



pupa. pi. 19, fig.8 (Group T a n y p us) 



hb Not culexlike 



c With long setae or filaments at caudal end 



(/ Caudal filaments very numerous and forming a caudal paddle, 

 pl.22, fig.l4, and pl.26, fig.15 

 V Thoracic respiratory organs a tuft of filaments, pi. 10, fig.2 



38. C h i r o n o m u s 

 ce Respiratory organs consisting of a main shaft with lateral hairs 

 or setae. Abdomen with setae and bristles. 



42. T a n y t a r s u s 

 dfl Caudal appendage with long setae 



c With eight long setae on each side of caudal appendage, pi. 30. 



figs. 4 and 5 25. C o r y n o n e u r a 1 e m n a e 



cc With a tuft of long setae on each side; thoracic respiratory 

 organ a simple fingor-likp jirocess. pi. 84. figs. 5 and 8 



31. H y d r o b a e n u s 

 cc With three or four pairs of short setae, a plate-like sucker or with a 

 paddle 

 d Plate-like sucker at caudal end, pi. 34, figs. 14 and 15 



29. T e 1 m a t o g e t o n ( St Paulii ) 

 rJd With two or three pairs of short setae or with paddle 



c Without thoracic respiratory tubes. Abdominal segments with 

 a fringe of conspicuous spines or setae or projections, pi. 48, 

 fig.13, and pi. 50, fig.lO in Bui. 68 N. Y. State Museum, 1903 



35. D i a m e s a 



37. T h a 1 a s s m y i a 



44. M e t r i o c n e m u s 



cc With respiratory tubes. AixjiMiiinal segments usually without a 



fringe of ].romineiit setae, pi. 21, fig.24, also pl.24, figs. 13, 14, 15 



39. C r i c t o p u s 

 41. Orthocladius 



'The larva of T h a 1 a s s o m y i a c o n g r e g a t a (an European species) 

 has a labium like Diamesa waltlii. 



