4 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 
tegula to tegula; mesoprescutum 
well defined; front wings with the 
medio-cubital cross-vein never less 
than three and sometimes four or 
five times the length of the trans- 
verse part of media. CEPHIDA 
EE. Anterior tibiw each with two apical spurs; 
propodeum not divided longitudinally but 
broadly emarginate behind. 
MEGALODONTID 4 (European) 
DD. Front wings with the transverse part of M, 
absent ; ovipositor retractile, thread-like, without 
prominent sheaths; antenn inserted low on the 
front beneath a prominent ridge which has the 
appearance of being the clypeus; vertex with a 
crown of tubercles; propodeum not divided 
longitudinally. ORYSSIDA 
CC. The radial cross-vein in the front wings with its caudal 
end distinctly apicad of R,, or wanting; the anterior 
tibiz with two apical spurs. 
D. Antenne four-segmented, the third segment about 
twice as long as the first two united, and about 
nine times as long as the fourth. 
BLASTICOTOMID2 
DD. Antennz variously formed, but not as above. 
TENTHREDINIDEA 
THE FAMILY SIRICIDA 
History or THE NOMENCLATURE OF THE GENERA 
There have long been recognized five groups, corresponding 
to what we now call genera, although not all of them, until 
within the past fifteen years, have been recognized as genera. 
Linneus in the tenth edition of the Systema nature grouped 
together under the comprehensive genus Ichneumon the species 
for which he subsequently erected the genus Sirex (1761). 
These were five in number, and include the types of three of the 
genera today recognized, as well as one belonging to another 
family. These originally included species of Sirex were: 
gigas, spectrum, juvencus, camelus, and marisca. 
The following year Geoffroy proposed the name Urocerus, 
figuring and indicating by a direct bibliographical reference 
