688 Pomona College Journal of Entomolooy 



except sometimes a spot towards uptx of submargiiial cell; apex of second vein 

 nearly twice as far from the first as from the apex of the third vein. I.engtii 

 2 mm. Described from eight specimens reared from larvae living in crude 

 petroleum near I.os Angeles, California." In February. 1899. Dr. L. O. Howard 

 (Scientific American, LXXX. p. 75) published a short article on the life-history 

 and gross anatomy of tlie Hy and its larva; a brief resume of which is given 

 here: 



On May 20, 1898, Dr. Howard received from Mr. C. G. Kellogg alcoholic 

 specimens of maggots said to live in crude petroleum near Los Angeles in very 

 great numbers.* After a fruitless attempt to send live specimens in petroleum 

 to Washington, Mr. Kellogg bred several adults from larvae in Los Angeles. 

 Fifty larvEe were placed in petroleum in a shallow dish in a glass-covered box 

 on June 18. In nine days the first maggots emerged from the oil, crawled to 

 the under side of the glass cover of the cage and pupated the following day. On 

 July 9 the first adults issued, twenty-two days after the larvK were placed in 

 the cage. Live maggots were later sent to Washington in moss saturated with 

 petroleum and one adult reared there. From these specimens Mr. Coquillet de- 

 scribed the species as new to science. There are no records in our entomological 

 literature of the habits of the species of Psilopa, to which genus this fly belongs. 

 The records of other related genera are as follows : Ephi/dra and Halmopofa in 

 salt pits in Europe, the former in salt pits in this country and in alkaline lakes 

 in the west; Teichomyza in human urine; Notiphila in stems of water plants; 

 Hydrellia in sap of trees ; Pelina and Parhi/dra in water — character of water 

 not mentioned. The family is apparently subaquatic — some forms breathe by 

 tracheal branchiae, others by protected sjjiraeles which can be elevated above the 

 water. The petroleum larva breathes by tlie latter method ; only the two spiracles 

 at the posterior end of the bod}' are functional, and these well protected. There- 

 fore the habitat is not so remarkable as might seem at first. The adult is easily 

 killed by petroleum. The food probably consists of dead organic matter 

 ("insects") caught in these pools of oil. Mr. S. F. Peckham in his Report on 

 the Technology and Uses of Petroleum, in the Tenth Census Reports, mentions 

 the presence of maggots in the oil and seeks to prove thereby the animal origin 

 of the petroleum. Dr. Howard thinks, however, that the food is entirely foreign 

 to the oil, thereby indicating nothing as to its origin. 



So far as is known to me this is the only article in entomological literature 

 dealing with the liabits and structure of the larva. 



The insect is probably found in many parts of the west where tliere are 

 petroleum fields. Tlie type locality is Los Angeles where the oil-fields are very 

 extensive. Prof. Esterley has seen them in the A\'hittier oil-fields so abundant 

 as to give the appearance of "uiaggotty carrion." In small pools of oil 

 shipped in for fuel at Pomona College, Claremont, Cal., I have found the 

 maggots in considerable numbers. In fewer numbers I have found them as far 

 north as Stanford Universitv. Further than tliis tlic distribution remains un- 



*Tho larvae were first discovered liy Mr. (ii-orjic t'oiiipcrc, tlicii HDrticultiiral Iiispeetor 

 in Los Angeles County. Heretofore he has not received duo crecht nor recojtnition. 



