JOURNAL OF ENTOMOLOGY AND ZOOLOGY 5 
only the species which had been described by Linneus (1758) 
as Ichneumon gigas, and which Linneus had subsequently 
placed in Sirex. That he had done so, however, was unknown 
to Geoffroy, whose conception of Urocerus was doubtless equiv- 
alent to that of Sirex by Linneus. While Geoffroy does not 
name any species of Urocerus, he describes one and only one, 
and by a definite bibliographical reference and a figure identi- 
fies it with Ichnewmon gigas of Linneus. The genus Urocerus 
is therefore monobasic, with Jchnewmon gigas as type. This 
interpretation is confirmed by Latreille who in 1810 definitely 
designed gigas as type. Fourcroy (1875) was the first to 
actually use a specific name in association with Urocerus, gigas 
being the name of the species that he then included. From 
that time until the end of the nineteenth century authors have 
used, some Sirex, others Urocerus, but always with the same 
meaning. During the past fifteen years, as a result of the work 
of Ashmead and Konow, Sirex has been generally recognized 
as the correct name and Urocerus as a synonym, and this is the 
status indicated by Rohwer (1911a). 
It had long been recognized that there were three species— 
groups within the old genus Sirex (excluding Tremex, which 
will be mentioned later), one containing gigas and its allies, 
another juvencus and its allies, and the third spectrum and its 
allies. For the latter Costa (1895) proposed the subgeneric 
name Xeris and Konow (1896) for the juvencus group the sub- 
generic name Paururus. These were shortly, and very appro- 
priately, raised to generic rank. Xeris contained the single 
species spectrum which is therefore its type. The type of 
Paururus is juvencus by designation of Rohwer (191lla). Sirex 
as thus restricted in the sense of Konow, Ashmead, and Rohwer 
was with the supposition voiced by Rohwer (191la) that gigas 
was its type. 
That, then, up to the present is the status of the old genus 
Sirex, gigas and its allies retained in it, juvencus and allies 
placed in Paururus, spectrum and allies in Xeris. 
But unfortunately Curtis (1829) definitely designated juven- 
cus as the type of Sirex, a fact known to Rohwer, and over- 
