356 EDWARD NORTON. 



sembles the iinngo, having the limbs laid along the side of the body 

 and breast. When the transformation of the insect take place in the 

 summer the imago is produced in the space of a month, but if the larvae 

 are not full grown uutil auttimn, the fly does not appear until the fol- 

 lowing summer. 



I'hese insects are among the largest of the order and from their pow- 

 erful flight, range over a wide extent of country, some of our species 

 being found both on the Atlantic and Pacific coasts. As the larvae re- 

 main a long time in the wood many of our species have been exported 

 in timber and are now common in Europe. 



The sexes vary much in color and size and it is difSeult to decide 

 which belong to the same species, unless they are taken together. 



Much of interest about the structure of habits of European species 

 may be found in the writings of Klug, Dahlbom, Westwood, Hartig, etc. 



Tahle to assist in dctermi.nmg species. 



A. O\'i])ositor not longer than the whole of abdomen: 



1. Antennie of one color; 



a. Apical cornus of 9 triangular, not spear-shajied : 



Legs black, abdomen black 1. Edwardsii. 



4. areolatus. 



Legs black, abdomen yellow banded 2. zonatus. 



Legs rufous, abdomen cyaneus 3. cyaaeus. 



Legs rufous, abdomen banded 5. nigricornis. 



2. Antennae banded with white or yellow ; 



b. Apical cornus spear-shaped; 



Base of all the tibise yellow fi. albicornis. 



7. abdominalis. 



9. tricolor. 



Base of hinder tibire yellow 8. Cressoui. 



All the tibiae and tarsi yellow 10. fiavicornis. 



B. Ovipositor longer than the whole body 11. caudatus. 



A. Ovipositor not longer than the whole of abdomen. 

 A. — Apical cornus of abdomen in female not si^ear-shaped. 



1. U. Edwardsii. 



Sirex Udwardsii, Brulle, Hist. Nat. Hym. iv, 645. PI. 45, fig. 1, 9 . 



Cyaneus; wings subviolaceous. Largest specimen, Length 1.32, with ovip. 

 1.41. Br. wings 2,20 inch. Smallest sijecimon, Length 0.56, with ovip. 0.62. Br. 

 wings 0.96 inch. 



Steel-blue, antennae, 20-, 22-, 23-, 25-jointed (in different speci- 

 mens) the first and third joints of equal length; head below vertex 

 coarsely pitted, vertex punctured and shluing; thorax closely pitted at 

 Hides, with a velvety appearance ; segments of abdomen velvety, very 

 finely punctured in middle; anal horn shining, coarsely punctured 

 and serrate, its form short, almost triangular; ovipositor the length 



