88 NEW YORK STATE MUSEUM 



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

 transversely wrinkled 

 » i Labium with its teeth rounded, pi, 20, fig.9 



35. D i a m e s a waltlii.^ 

 ii Labium with its middle tooth broadly truncate 



37. Thalassomyia fusca 

 Note. — See addenda for several anomalous species. 



Pupae 



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



water, pl.17, fig.ll ( Ch^oiip G e r at o p o g on) 



aa Pupa not as above 



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



pupa, pi. 19, fig.8 ( Group T any p us) 



1)1) Not culexlike 



c With long setae or filaments at caudal end 



cl Caudal filaments very numerous and forming a caudal paddle, 

 pl.22, fig.l4, and pl.26, fig.l5. 

 e Thoracic respiratory organs a tuft of filaments, pi. 16, fig.2 



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

 ee 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 

 dd Caudal appendage with long setae 



e With eight long setae on each side of caudal appendage, pi. 36, 



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



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

 organ a simple finger-like process, pi. 34, 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) 

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



e Without thoracic respiratory tubes. Abdominal segments with 

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

 fig.l3, and pl.50, fig.lO in Bui. 68 N. Y. State Museum, 1903 



r 35. D i a m e s a 



-i37. Thalassomyia 



[44. Metriocnemus 



ee With respiratory tubes. Abdominal segments usually without a 



fringe of prominent setae, pi. 24, fig. 24, also pi. 24, figs. 13, 14, 15 



39. Cricotopus 

 41. Orthocladius 



'The larva of Thalassomyia c n g r e g a t a (an European species) 

 has a labium like D i a m e s a waltlii. 



