208 PROC. ENT. SOC. WASH., VOL. 23, NO. 9, DEC., 1921 



1921. Mr. Thompson states that the "specimens were collect- 

 ed on Elderberry (Sambucus sp.), and borings in the stems 

 indicated that they breed in the stems of this host. " Paratype 

 A is a male, and is similar to the type except that each elytron 

 has an additional oblong bluish-black spot near the apex. 

 Paratype B is a female, and is similar to the allotype except that 

 it is smaller, measuring only 16 mm. in length and 5 mm. in 

 width. 



This species belongs to the section of Desmocerus in which the 

 sexes differ in color. It is allied to D. piperi Webb, but can be 

 distinguished, however, from that species by the elytra being 

 smoother, with the tips more truncate; females with the elytron 

 opaque black and intervals finely granulated; males with the 

 elytron marked with bluish-black spots and more strongly 

 attenuate posteriorly. It resembles D. californicus Horn very 

 closely in the punctation of the elytra but can be separated 

 from that species by the sexes being differently colored. 



A NEW ASILID FLY FROM THE MADEIRA ISLANDS. 



BY T. D. A. COCKERELL. 



In the Museum of the Seminario at Funchal is a considerable 

 collection of Madeira Diptera, determined by Becker. In it 

 I found only one Asilid, Machimus madeirensis of Schiner. My 

 wife took a specimen of this species at Camcal, Madeira, 

 January 5, 1921. One other Asilid is recorded from Madeira, 

 Tolmerus novarensis Schiner. The Canary Islands possess a 

 much richer Asilid fauna, with four species of Promachus, six 

 of Epitriptus, two Stictopogon, and one each of Heligmoneura, 

 Tolmerus and Habropogon. There are many indications that 

 the Canaries, or at least the more eastern ones, were united with 

 the African continent during part of Tertiary time. The 

 Madeiras, on the other hand, appear far more isolated, and in 

 general have the biota of oceanic islands. It there was ever 

 any land connection with the continent, it was as far back as 

 the Mesozoic 



In the island of Porto Santo, 23 miles from Madeira, there is 

 an extremely distinct snail-fauna, and a considerable number of 

 endemic insects, particularly Coleoptera. On the southern 

 slopes of the Pico de Castello, in January, I collected two males 

 and a female of a Machimus which at first sight seems identical 

 with that of Madeira. It is, however, rather smaller, and close 

 inspection shows that it is certainly distinct, with the following 

 characters: 



Machimus portosanctanus, n. sp. 



Fcmcde (Type). About 13 mm. long, wing 9 mm.; black, with the tibiae 

 suffusedly dusky reddish basally; face narrow, white with a faint yellowish tint; 



