290 THE CANADIAN ENTOMOLOGIST. 



Pronotum not or scarcely visible from above, more or less hidden by 

 the front margin of the mesonotum, which is strongly developed, the 

 furrows on the latter distinct ; maxillary palpi 5- 

 jointed , (8) Aphelopus, Dalman. 



Family XXXIII. — Trigonalidse. 



This family, on account of its anomalous character, is one of the 

 most interesting in the superfamily Vespoidea. The species are 

 extremely rare, although widely distributed, and only four genera are 

 known. 



The family is usually associated with the Evaniidae and the 

 Ichneumonidse, in my opinion an unnatural position for it. 



Prof. Westwood, however, evidently had a true appreciation of the 

 affinities of his genus Trigonalys, the type of the family, for when he 

 described it, in 1835,. he observes : " Genus anomalum familice dubice 

 caput et anl entice Lydce, abdomen Mutillce. Alarum nervi ut in Myrmosa 

 dispositi." Again, five years later, in his Introduction Mod. Classif. 

 Insects, Vol. II., p. 215, he wrote: "I may here mention another 

 anomalous genus, which I have described under the name Trigonalys, 

 having somewhat of the aspect of a male Mutilla, but with the head 

 flattened and the antennae longer, very slender at the tips, and composed 

 of 23 or 24 joints, very like those of Lyda ; the legs are simple and the 

 abdomen punctured. The veins of the wings are nearly as in Myrmosa 

 and Mutilla Europrea male." 



The responsibility for the removal of Trigonalys to the Terebrant 

 Hymenoptera appears to be due to Shuckard, an able British Hymenop- 

 terologist, who, in 1851, deceived by the anomalous character of the 

 antennae and the two-jointed trochanters, incorrectly associated it with 

 Aulacus, Jurine, into a family to which he gave the name Au/acidce, 

 placing the family next to the Evaniidse. 



Mr. Cresson, in his Synopsis of the North American Hymenoptera, 

 published in 1888, properly established the family Trigonalida?, but has 

 incorrectly placed it between the families Evaniidai and Ichneumonidse. 



The Trigonalida.', in my opinion, have nothing to do with the 

 Evaniidse or the Ichneumonidre; they are far removed and widely separated 

 by many salient characters, and represent a natural group in the superfamily 

 Vespoidea. Their affinities, to me, seem to be clearly with the Bethylidae, 



