688 Pomona College Journal of Entomology 



except sometimes a spot towards apex of submarpinal cell ; apex of second vein 

 nearly twice as far from the first as from the apex of the third vein. I,en};tli 

 2 mm. Deserilx'd from eight specimens reared from larv* living in crude 

 j)etr()leum near I,os Angeles. California." In February, 1899, Dr. L. O. Howard 

 (Scientific American, I, XXX. p. 7.i) ))iil)lislied a sliort article on the life-history 

 and gross anatomy of tlie Hy and its lar\a; a brief resume of wliich is given 

 here : 



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

 s|)(eimens of maggots said to live in crude ))etroleum near Los Angeles in very 

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

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

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

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

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

 .luly 9 the first adults issued, twenty-two days after the larvs were placed in 

 the cage. Live maggots were later sent to Wasliington 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 llalmopota in 

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

 in the west; Teichomtjza in human urine; Xofiphila in stems of water plants; 

 Ili/drellia 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 branchise, others by protected spiracles which can be elevated above the 

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

 at the posterior end of the body 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 habits and structure of the larva. 



The insect is prob.ably found in many parts of the west where there are 

 petroleum fields. The type locality is Los Angeles where the oil-fields arc very 

 extensive. Prof. Esterley has seen them in the Whittier oil-fields so abundant 

 as to give the ajjpearance of "maggotty carrion." In small pools of oil 

 shijipcd in for fuel at Pomona College, Claremont, Cal., I h.ive found the 

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

 north as Stanford Universitv. P'urtlier tlian this the distribution remains un- 



*The larvae were first discovered liy .Mr. Georjfe CdiiijH'rc, then Hin-ticiilturnl Inspector 

 in Los Angeles County- Heretofore he h.is not received due credit nor recognition. 



