140 THE ENTOMOLOGIST. 



description of /. sanguinator, Rossi, in Gravenhorst's I. E. iii. 

 918; but as the description is short there must be some doubt 

 about it. Ichneumon sanguinatorius, Gr., I. E. i. 295, synonym 

 of Amblyteles occisorius, is quite a different species. Probably, 

 on account of the slightly exserted ovipositor, Marshall placed 

 I. sanguinator in the genus Phygadeuon with Cryptus sanguinator, 

 Desvignes, as a synonym, which must be a mistake. Desvignes, 

 in the British Museum Catalogue, gives both Ichneumon san- 

 guinator (p. 29) and Cryptus sanguinator (p. 58). From the above 

 it is evident that sanguinator, Rossi, must be added to Marshall's 

 list. Its place in our table will be (vol. xiii. 216) section 12, B. a. : — 



=1= Thorax and scutelluiu yellow-marked. - erythraus, male and female. 

 *=!= ,, ,, not so marked. - - sanguinator, female. 



The male comes in section 6 (vol. xiii. 181), — A. Abdomen, 2nd 



to 4th segments red ; and after " a." : — 



f Antennae and hind tarsi white-ringed. - sanguinator, male, 4-|- lines. 

 ff „ ,, not white-ringed. 



In structure it might be placed in Holmgren's division 8, if in 

 any of his divisions ; it differs from all, but comes nearest to this. 

 It might go into B. of section 7, but for the aciculate 1st segment ; 

 this latter mark wants adding to the description of section 8 to 

 make it exact. — J. B. Bridgman ; 69, St. Giles' Street, Norwich. 



Thryptocera bicolor. — At the end of May or beginning of 

 June last, I had fifty larvae emerge from a full-fed caterpillar of 

 Bombyx quercus. On the 1st May the first imago made its 

 appearance, which proved to be a specimen of this very rare 

 dipteron. Dr. Meade very kindly identified it. Mr. Walker, in 

 his 'Insecta Britannica,' mentions that there was one specimen 

 in Mr. Stephens's collection. Herr Schiner, in the ' Fauna 

 Austriaca,' says he had one specimen which was bred from 

 Bombyx quercus, and adds that it has also been bred from P. 

 mediella. Dr. Meade, in his letter to me, states that he has one, 

 a German specimen, and that those I sent him are the first 

 British ones he has seen. The larva of Bombyx quercus was 

 taken at Falmouth. — G. C. Bignell; Stonehouse, May 5, 1882. 



Note on Parasitic Diptera. — It seems that occasionally flies 

 which are not usually parasitic in their habits become so under 

 particular circumstances, or in certain localities. The causes of 

 this peculiarity are very obscure, and the fact is very interesting ; 

 so that any well- authenticated instance is worth recording. In 



