192 THE ENTOMOLOGIST. 



paper as new to our fauna, and others are very likely to occur if 

 searched for. 



The writer merely hopes in these notes to pave the way for 

 further and more detailed work by enabling the collector to 

 name his material correctly. With this end in view, tables for 

 determining the adults are given, with brief descriptions of each 

 species. The common gnat is so well known that no general 

 description is necessary — all Diptera with a long proboscis and 

 the same type of wing-venation as is found in Culex pipiens 

 may be assumed to be " mosquitos." This term is rightly 

 applicable to any member of the group, and should not be 

 limited to a particular species or genus. 



The following artificial key may serve as a rough guide in 

 the identification of a specimen, but its proper generic position 

 should, of course, be ascertained by the aid of the tables : — 



A. Tarsi ringed with white at the bases of the joints. 



a. Metatarsi without a median pale ring. 



0. cantans, 0. annulipes, 0. vexans. 



b. Metatarsi with a median pale ring. 



Th. anmdata, Teen, richiardii. 



B. Tarsi pale-ringed, the rings embracing both ends of the joints. 



a. Abdomen with a median longitudinal pale stripe, more or less 



interrupted. 

 0. dorsal is. 



b. Abdomen without such stripe, but with whitish bands at the 



bases of the segments. 

 Th. morsitans, Th. theobaldi. 



C. Tarsi entirely dark. 



a. Abdomen not scaly. Anopheles. 



b. Abdomen scaly. 



i. Segments of abdomen with complete basal pale bands. 



0. divcrsus, 0. nemorosus, 0. salinus, C. pipiens. 

 ii. No complete pale bands on abdomen. 

 0. lateralis, A. cinereus. 



Table of Genera. 

 Males (antenna plumose) : 



1. Scutellum rounded ; legs very slender ; abdomen 



without scales 1. Anopheles. 



Scutellum more or less trilobed ; abdomen scaly 

 (the scales are, of course, easily rubbed off, but 

 will be quite evident except in very bad speci- 

 mens) 2. 



2. Palpi very short 3. Aedes. 



Palpi long, rarely shorter than the proboscis . 3. 



3. Last two joints of palpi more or less swollen, and 



never curved upwards 4. 



Last two joints of palpi quite thin, curved upwards 6. Culex. 



4. Last joint of palpi distinctly thicker than the 



penultimate 5. Theobaldia. 



