1913] Observations on Chcetotaxy of Calliphonnae. 261 



tion taken at some distance from buildings. Sericata is more 

 commonly present either inside or very near buildings, while 

 caesar may be taken in either situation, but more frequently 

 along with sylvarum. It would be of considerable interest to 

 study the distribution of these species over a more extensive 

 area. 



In order to get an approximate estimation of the percentage 

 of individuals abnormal in chaetotaxy, I have added the seri- 

 catas and find them as follows: 



Normal — 2,479 individuals. Abnormal by reduction — 47 

 individuals or 2 %. Abnormal by addition — 23 individuals or 

 1%. Abnormal by reduction and addition — ■ 1 9 — 3,2, 2, 4, or 

 .04%. 



The variants by reduction are here 10 cf d^ and 37 9 9 , 

 while the variants by addition are 2 cf cf and 22 9 9 . The 

 excess of females is of course due to the fact that the flies were 

 taken at meat. 



Some of the flies were bred to show the character of the 

 progeny, and these showed results as follows: 



L. sylvarum: 9 — 3, 3, a .' be, 3, with 2 very small ab. br., taken by pond 



near Bussey, Aug. 12, gave all females in progeny as follows: 

 9 9 9—3, 3, 3, 3, ab. br. lacking. 



2 9 9—3, 3, 3, 3, with 2 small ab. br. 

 1 9 — 3, ! abc, 3, 3, ab. br. lacking. 



3 9 9—3, 3, a / be, 3, ab. br. lacking. 



1 9 — 3, .' abc, ! abc, 3, ab. br. lacking. 

 This suggests that an extra post-sutural bristle may be inherited. 

 L. ccEsar: 



9—3, 2, 2, 3, from Bussey Pond, Aug. 14, gave 18 d'd'—S, 2, 2, 3. 



13 9 9—3, 2, 2, 3. 1 cf— 3, b, 2, 3. 



9—3, 2, 2, 3, from Bussey Pond, Aug. 10, gave 13 9 9—3, 2, 2, 3. No 

 males. 

 L. sericata: 



9 — 3,3, 3, 3, from Bussey Institution, July, gave 

 51 cfcT- 3, 3, 3, 3. 



35 9 9—3, 3, 3, 3. 1 9—3, 3, a! be, 3. 



9 — 3, 3, 3, 3, from Bussey Institution, Aug. 5, gave 



71 d^c^— 3, 3, 3, 3. 59 9 9—3,3,3,3. 



3 cTcf- 3, 3, a./ be, 3. ' 2 cf cf— 3, a .' be, 3, 3. 



1 cf —3, a .' be, a ! be, 3. 19 —3, a ! be, 3, 3. 



1 9 —3, 3, a .' be, 3. 

 9 — 3, 8, 3, 3, from Bussey Institution, July, gave 



