327] LARVAE OF THE TENTHREDINOIDEA—YUASA 9 



definite groups on structural differences, and that they are best dealt 

 with by considering them simply as subfamilies. In general the systems 

 of Konow and Rohwer are, with the exceptions noted below, more in 

 accordance with each other in their essential features than either one of 

 them is with that of MacGillivray. A comparison of these three schemes 

 brings out various points of interest. As far as the major groups are con- 

 cerned, (1) all are in agreement in associating Xiphydriidae with Siricidae; 

 (2) Konow and Rohwer agree in placing Siricidae and Siricoidea closer to 

 Lydidae and Megalodontoidea respectively than does MacGillivray, as 

 also in associating Megalodontidae with Pamphiliidae and Xyelidae and 

 Pamphiliidae with Cephidae; (3) Konow and MacGillivray agree in the 

 relation of the Blasticotomidae to Xyelidae and Pamphiliidae; (4) Rohwer 

 differs radically from them in his arrangement of the Blasticotomidea, 

 which he places between the Argidae and Tenthredinidae in his super- 

 family Tenthredinoidea; and, finally (5), Rohwer (1917) is unique in 

 creating a third suborder of Hymenoptera, Idiogastra, for the Oryssidae, 

 In respect to the arrangement of the subfamilies and tribes of the Tenth- 

 redinidae, as restricted by MacGillivray, the striking dissimilarity of these 

 authorities in assigning different rank to more or less related groups is 

 well illustrated in their treatment of the Emphytinae, Selandriinae, and 

 Lycaotinae. According to MacGillivray Konow's tribe Selandriades of his 

 family Tenthredinini corresponds to the three subfamilies just mentioned, 

 while according to Rohwer it embraces not only these subfamilies but also 

 another — Allantinae; that is, Rohwer considers the Emphytinae related 

 to the Tenthredmidae thru the tribe Allantini, which, together with the 

 tribes Taxonini and Eriocampini, constitute his subfamily Allantinae. 

 The Emphytinae and Lycaotinae are also related, according to Rohwer, 

 to the Blennocampinae thru his subfamily Empriinae, which contains, 

 besides Empriini and Lycaotini, the tribe Blennocampini. MacGillivray 

 and Rohwer agree in regard to the Cimbicinae to the extent that they 

 both consider it a compact group. Konow differs radically from these 

 writers by associating his tribe Syzygoniides with the Cimbicides and 

 Abiides. In regard to Konow's Nematides and Lobocerotides, the three 

 systems agree fairly well. The affinities of the Blennocampinae, Fenusinae, 

 and Scolioneurinae are recognized by MacGillivray and Konow. Rohwer 

 and Konow agree, as do all other systematists except MacGillivray, in 

 treating the Diprioninae and Monocteninae as allied groups inseparable 

 into subfamilies. Konow's subfamily Lophyrini, however, is a hetero- 

 geneous group and includes such widely separated groups as Acordule- 

 cerinae and Diprioninae. 



The classification proposed by MacGillivray is based upon a critical 

 investigation of an essential structure, the wing, and is a logical conclusion 

 of the application of the taxonomic principles promulgated by Comstock 



