March, i 9 o 5 .] Dyar: North American Mosquito Larva. 



1. Mouth hairs in a pair of pencils folded outward and hooked at tip; larva: 



predaceous " "' '"'"' , 



Mouth hairs diffusely tufted, folded inward, not hooked ; larvae not wholly preda- 

 ceous, feeding on vegetable matter • " 3 ' 



2 Lateral comb of the eighth segment a patch of spines Psoropkora cihata. 



Psoropkora howarmi- 



A lateral plate on the eighth segment Megarhinusperrtoricmsis- 



Megarhmus minus. 



3 Air tube short, sessile, larvse floating at surface of water 4- 



Air tube longer than wide ; larva; floating below surface 7; 



, r , , ,, Anopheles barber?.. 



4. Teeth of comb of equal length t 



Teeth of comb of two sizes, long and short ••■ • > 



5. Teeth of the lateral comb with large branches within Celha albipes 



Teeth of the comb with line, obscure pectination only 



6 Secondary teeth of the comb less than half as long as the primary ones. 



; Anopheles crucians. 



Anopheles maculipenm . 



Secondary teeth of the comb over half as long as the primary ones. 



J Anopheles punchpennis - 



Anopheles franciscanus. 



7 Air tube linear on its outer half, armed with hooks.... Taniorhynchus periurbans 



Air tube conical, fusiform or straight, regularly tapered • • 



8. Abdominal hairs short stellate tufts; body ptlose Howardma walkert. 



■ Hairs of the first two abdominal segments long, the rest short, stellate. 



Uranottznici sapphinna. 



Uranotania socialis. 



I ranoticnia loewii. 



Abdominal hairs long, subequal, diminishing gradually posteriorly 9. 



9 . No ventral brush ; anal processes two, dilated Wyeomyza smUktu 



Ventral brush present 



,„. Ana, processed t „b e short with row of hair u,f S ; «■»«-£ 



II. 



Anal processes four or none ; not two •••••• ■ 



„. Air tube short, 3 X « or less, or if longer with but a single ban- tuft ; antennal 



tuft at the middle of the joint without set-oft ••••• 



Air tube long, 4 X 1 or over, with usually many hair tufts beyond the pecten ;• 

 anttL with the terminal portion slender, the tuft usually beyond the 



49- 



l 2 AnTennVben't Shaped! 'swollen ^hou^'two'of the stout terminal hairs removed 

 1 ....Litlex discolor.. 



towards the base ' . ,.. 



Antenna, slightly swollen, narrowed at outer two thirds beyond ^^J£ 



basally '""" "'.'". T _ 



Antenna with the tuft at the middle of the uniformly shaped joint ■■■ ^ 



13. Seventh abdominal segment with a large dorsal plate CuUx signify 



Seventh segment without a plate \""i"\'[ T e 



14. Comb of eighth segment of few spines in a single or partly double row 1$. 



Comb of many spines in three or more rows 



