110 PROC. ENT. SOC. WASH.. VOL. XIV, 1912. 



Atherix and Symphoromyia. It is easily conceivable, from 

 what we know of other groups of blood-sucking Diptera, that 

 the habit is restricted to certain species of those genera. In 

 the case of Symphoromyia it appears somewhat strange that 

 no further records have appeared, as some of the species appear 

 to be fairly common in the far west. This, however, is prob- 

 ably attributable to the fact that the statement of so emi- 

 nent an observer as Osten Sacken has been generally accepted. 

 In the case of the Chilean Dasyomma it is not strange that, 

 in a country so poorly known entomologically, Philippi's 

 observation, should it be correct, has not been confirmed. 



In the case of the Atherix from Mr. Crawford, some doubt 

 arose in my mind from the superficial resemblance of the 

 specimen to certain of the more slender Tabanidse, certain 

 Chrysops, and Dicheloccra. This doubt was strengthened 

 when I examined the South American Leptida? in the Museum 

 collection and found that, of two specimens sent in by E. C. 

 Reed as Dasyomma cinerascens, one, and the one bearing 

 his original label ' Trichopalpns cinerascens" is a tabanid. 

 On a statement of the unsatisfactory character of our records 

 Mr. Crawford kindly sent me the following communication, 

 which leaves no room for doubt that Atherix long ipes \$ a 

 genuine blood-sucker. 



In regard to the blood-sucking Leptid, Atherix longipes, I am very 

 sure of my statement that it was that and not a Tabanid which I caught 

 thus. There were a large number of the flies which attacked both me and 

 my horse in the mountains a few miles back of Oaxaca. The bite was 

 exceedingly painful and caused more alarm among the horses in my outfit 

 than any other fly. I was so interested in a blood-sucker, which appar- 

 ently was not a Tabanid, that I put a number in a separate killing-bottle, 

 taking them all in the act of biting either me or my horse, and when I 

 pinned them I took special pains to append a note on the pins. So you see 

 I am positive beyond a chance of mistake. Moreover, there are no 

 Chrysops orDichelocerahomQ&xa.c& in my collection so I am doubly sure! 



The occurrence among the Leptid;y of isolated species with 

 the blood-sucking habit is not so surprising when one considers 

 that the flies of this family are reported to bepredaceous upon 

 other insects. From piercing the integument of an insect to 

 puncturing the skin of a warm-blooded animal is but a step. 

 Besides, similarly, isolated cases occur in other families of 

 Diptera among the species which have mouthparts fitted for 

 piercing and sucking. Thus, in the family Blepharoceridae, in 

 which the females are generally so organized, the predaceoue 

 habit is general, while a single species (Cnnipini torrentium 

 F. Miiller) is an habitual blood-sucker. Again, in the family 

 ChironomidsB, subfamily Ceratopogonime, there are species 

 which attack other insects to suck their juices, while certain 

 others are well known for their attacks on the higher animals. 



Actual date of issue, June JQ, /Of 2. 



