73 



D^•AK TI. ('..). Notes on the North American Species of Chocroporpa 

 (Dipfcera, Culicidae). liisccutoy Inscitiac McnslniKs, Washington, 

 D.C., ix, no. 1-3, January-March 1921, i)p. 37 39. 



The synonymy of various species is discussed, undC i(lcx{C/ioeyoporpa) 

 degustator, sp. n., is described. 



Dyak (H. G.) & Ludlow (C. S.). Two new American Mosquitoes 



(Diptera, Cuhcidae). — Insccntor Inscitiac jSIcnstruns, Washing/on, 

 B.C., ix, no. 1-3, January-March 1921, pp. 46-50. 



The new species described are Ciilex [Mdanoconion) hoinocopas, 

 from New Orleans, possibly imported from Nicaragua, and C. 

 {Choeroporpa) dysmathes from the Panama Canal Zone. A key is 

 given to the described species oiMelanoconion, based on the characters 

 of the male hypopygium. 



Hackek (H. p.). Federated Malay States Malaria Bureau Reports. — 



ii, November 1920, London, 1921, 47 pp., 1 hg., 2 plans. 

 [Received 17th February 1921.] 



This report continues the publication of data collected by the F.M.S. 

 Malaria Bureau [R.A.E., B, viii, 84], and contains a record of the 

 observations made during the three preceding years. Attention is 

 called to a number of recent changes in nomenclature [R.A.E., B, 

 viii, 49], Anopheles rossi var. indefiniius, Ludl., becoming A. vagus, 

 Don., the variety recorded as A. rossi, Giles, in vol. i, becoming 

 A. suhpidus, Grassi, var. malayensis, nov. ; and A. hunter i, Strickl., 

 becoming A. separatus, Leic. 



The first report deals with the distribution of Anophelines in the 

 Brickfields Road area of Kuala Lumpur. It was desired to find 

 out whether the eradication of the swamps was advisable, and also to 

 trace the source of a number of malaria cases from this area. 



A method for grouping the species found as representative of f aunistic 

 areas has been introduced and will be applied to further results as a 

 method for elucidating problems of distribution. It is based on the 

 numerical frequency with which the various species are found together 

 in nature, ancl thereby shows which species are most commonly found 

 in the same breeding-place in association with any given species. 

 The number of times a species is found alone, added to the number of 

 times it is found in association in the same breeding-place with each 

 of the other species, gives the total number of " association units" 

 available for that species. It is necessary for the purpose of com- 

 parison to express the component parts of this number as percentages, 

 and it is permissible to do so if the total number of association units, 

 on which this series of percentages is based, is also shown. A con- 

 venient term for the percentage association of one species with each 

 of the other species is " association value." This method does not 

 depend on personal descriptions of individual breeding-places, but is 

 built up quite mechanically from the records of the species found in 

 a given number of breeding-places. 



The most widely distributed species in the area were the large-pool 

 breeders, A . barbirostris and A . hyrcanus ; the recognised malaria- 

 carriers, A. fuliginosus and A. aconitus, although not numerous at 



(■imi) Wt.P3/18i l.JUO 5/21 Harrow 



