August, '16] PARKER: SARCOPHAGA ALDRICHI 441 



possible relationship rather than as a convenient specific character. 

 These hairs are always in line with the spiracles on each side and the 

 significance of their presence is not quite clear, unless as representing 

 the remains of the vestigial sixth abdominal segment, the so-called 

 fourth ventral plate of taxonomy being its sternum. 



Among material examined from the Gypsy Moth Laboratory at 

 Melrose Highlands were a number of specimens of S. aldrichi recorded 

 as reared from pupse of Porthetria dispar (L.), collected at Melrose, 

 Wakefield, North Saugus, Woburn, North Andover, Beverly, Essex, 

 Topsfield, Gloucester, and Swampscott. Certain of these cities should 

 appear under the range, but there are no means of discrimination. Of 

 Sarcophagidce collected at Lunenburg, Massachusetts, during the 

 summer of 1914 by R. T. Webber of the Gypsy Moth Laboratory, this 

 species is by far the most numerous. 



I am indebted to Professor J. M. Aldrich for the following notation 

 which he received from Professor LaAvson Csesar, Provincial Entomolo- 

 gist of Ontario: "In the last three years forest tent caterpillars (M. 

 disstria) have been very abundant in the eastern parts of Ontario. 

 Last year when visiting that part of the province on some entomological 

 work, I observed that nearly 90 per cent of the cocoons opened in 

 July showed the presence of a dipterous larva, which I supposed would 

 be a Tachinid. However, from about two dozen of these cocoons 

 brought back with me to Guelph there have emerged eight Sarcopha- 

 gids and no Tachinids." Specimens were determined by Dr. Aldrich 

 as *S. aldrichi. 



While examining material collected at Lenox, Massachusetts, during: 

 June, 1915, by C. W. Johnson of the Boston Society of Natural History^ 

 this species was noted to be very numerous. Conversation with Mr. 

 Johnson established the fact that caterpillars of Malacosoma disstria 

 Hiibner were abundant in that locality. 



Except for a few scattered specimens captured in isolated localities, 

 the only records the writer has of the occurrence of this species in 

 abundance have been where there were larvae of either Porthetria dis- 

 par or Malacosoma disstria, especially the latter. The true status of 

 this species in the economy of nature may be a point worth determina- 

 tion. 



