I9I4-] E. Brunetti : Review of Genera in Culicidae. ig 



generally 4-jointed form in the Nemocera, and the (generally) 2 or 

 3-jointed form in the bulk of the rest of the diptera In some 

 groups they are only one-jointed and are then of but slight value 

 in restricted classification. One of the earliest classifications was 

 built primarily on the palpi; long (4 or more joints) in Nemocera, 

 and short (2 or 3 joints) in the Brachycera (i.e. the remaining 

 diptera exclusive of Pupipara) ; and as a ready method of dividing 

 the order into two great groups there is even to-day no better 

 method, especially for the general entomologist. 



The palpi in Culicidae vary more than any other organ and to 

 a greater extent than in the allied nemocerous families. 



Theobald, even in his first volume (p. 4) says the palpi " vary 

 in each group, and are of specific but not always generic value," 

 and in a footnote to page 16 adds, " the subject of the palpi is a 

 very complicated one, and will take some time to work out. 

 Arribalzaga figures the constrictions as joints." 



In his latest volumes (iv, 15) he says "the classification by 

 means of the relative lengths of the palpi, is, however, not satis- 

 factory, as we get so many intermediate forms," and again (v. 

 Intro, p. vi), " owing to the dense coating of scales, what look like 

 palpi of 3 segments may really consist of 4, 5 or 6." 



It is difficult to obtain definite information as to their struc- 

 ture in many genera without mutilating the unique types, a 

 course from which most authors have refrained. 



The cr' palpi is said by Theobald to be especially liable to 

 shrinkage after death, rendering exact examination difficult. 



Besides it is not only the density of the scales, but the actual 

 ill-defined nature of the joints themselves in many species that 

 constitute a real stumbling block, though the taxonomic value in 

 such cases must be considered to be correspondingly reduced. All 

 degrees have been seen to occur from palpably mere constrictions 

 to well-defined joints. 



This uncertainty has led many writers to speak of the apical, 

 penultimate and antepenultimate joints, by this means avoiding 

 any statement of the exact number instead of the ist, 2nd and so 

 on, counting from the base, as is invariably done in diptera. 



Possibly under the circumstances this is the safest method, 

 but none the less it is consequently impossible for a reviewer to be 

 precise in his deductions. 



Study is also not facilitated by the obscure use of terms, some 

 authors for instance speaking of a joint being "larger" than 

 another when they presumably mean longer. 



The figures do not always agree with the descriptions, as for 

 example Anopheles maculatus, Theob, (Monog. i, 171), though 

 several cases of discrepancy could be mentioned; whilst further 

 ones of ambiguity of description are numerous. Patton figures 4 

 distinct joints to A. {Nyssorhynchus) tibani cf , the first two quite 

 long and the 3rd and 4th subequal to one another, and of about 

 the normal lengths of the two apical joints in Anopheles, yet h? 

 does not say whether 4 joints are definitely present or not. 



