30 Records of the Indian Museum. [Voi,. X, 



The cf Genitalia, — Though the value of the cf genitalia in 

 allied families to the Culicidae {Tipulidae, Mycetophilidae, and, 

 I believe, Chironomidae also) has long been known to diptero- 

 logists, Osten Sacken describing and figuring them very conscien- 

 tiously in his classic monograph of the North American Tipulidae 

 brevipalpi in 1869, it is not until Theobald's 4th volume of his 

 work (pp. 7, 9) that the subject is broached in this family by him, 

 nor do contemporary authors deign more than an incidental 

 reference to these parts, ignoring them altogether in the specific 

 descriptions. That culicidologists should ignore the male organs 

 is not to be wondered at considering the pernicious precedence 

 consistently accorded by them to the $ , in spite of dipterologists 

 having pointed out that characters and especially external mark- 

 ings are almost always more fixed in the cf than the 2 and, as the 

 former sex is less bloodthirsty there is, in specimens of it, less 

 discoloration due to imbibed blood. 



Dr. Dyar says " genitalic divisions are more natural than 

 those recently founded on scales and palpi," but Theobald, reply- 

 ing (Monog. iv, 13) asserts that he himself supports characters 

 "which are common to both sexes, such as the scales " adding 

 " such we find to be the case, not only from a structural but also 

 from a bionomic point of view." Theobald observes (i, 327) that 

 the cf genitalia " vary so much in closely related gnats," but the 

 subject is then shelved. 



The genera set up by Felt, Culicada, Culicella, and the allied 

 others exhibit a reasonable amount of variation in these organs, 

 but not sufficient to separate them generically from Culex (s. latu). 

 In fact far more diversity is found in them in the very large and 

 homogeneous genus Tipula, whilst they vary widely within the 

 limits of the genus in many cases in allied nemocerous families. 

 Generic subdivision on these organs alone is to be deprecated. 

 Dr. Dyar (Proc. Ent. Soc. Wash, vii. No. i — 1905) gives a table of 

 genera (including four new ones), reproduced by Theobald (iv,ii), 

 constructed solely on the cf genitalia. Felt (N. York State Mus. 

 Bull. No. 79, Ent. 22—1904) also endeavours to classify similarly, 

 supplementing this character by those of the veins, the scales and 

 the larvae, but his distinctions do not appeal to me as at all 

 convincing and it does not seem conceivable that all the characters 

 hold good in all his genera. 



It may well be that the cf genitalia are much less diverse 

 than in some allied families, and if used with caution and in con- 

 junction with other characters they should prove a useful adjunct 

 in discriminating species, but they are hardly likely to prove of 

 generic value in this family except possibly in rare instances. 



The female genital organs in diptera hardly ever offer much 

 in the way of distinctive characters. 



The Larva. — Classification by larval characters is not easily 

 criticised unless one has some considerable knowledge of this 

 branch of study. Perhaps Messrs. Dyar and Knab have advanced 

 farthest in this line, and in their view the principal features in the 



