22 Mr. H. W. Bates on the 



inevitable, and the more attentively the Longicoms are studied 

 the more hopeless rigid definitions of genera and subfamilies 

 appear. 



The RMnotragince are a subfamily of the same section of 

 the CerambycidEe to which the familiar genera Callichroma^ 

 Necydalis, &c. belong, i. e. having finely faceted eyes. They 

 are remarkable for the very general abbreviation of the elytra 

 in the species, and the mimetic resemblances that many of them 

 bear to wasps, bees, Ichneumonida3,and so forth — aresemblance 

 which is much aided by the subrudimentary condition of the 

 elytra and the prevailing style of coloration. In tlie imago 

 state they frequent flowers, in company with the Hymenoptera 

 many of them resemble, and are very nimble fliers, probably 

 in consequence of the abbreviation of the el}i;ra and great 

 development of the membranous wings. An almost universal 

 character of the group is the large volume of the eyes, especially 

 of the lower lobes, which in the males nearly meet in front : 

 this forms the nearest approach to an exclusive character of 

 the group ; but it disappears in some few species. The head, 

 too, is very generally elongated below the eyes, forming a 

 muzzle ; but this character exists in several other subfamilies 

 of Cerambycidffi. The palpi are short, and their terminal joints 

 nearly cylindrical or cylindi-ic-ovate, truncated at the apex. 

 The antennge are almost always more or less serrated from the 

 sixth joint ; and the third to sixth joints are furnished with 

 setae on their outer sides. The thorax is cylindrical or ovate, 

 always imarmed at the sides. The prostemuni forms a distinct, 

 though narrow, level plate betu'cen the anterior coxa3 ; and the 

 epistevna of the metasternum are always triangular and very 

 broad in front. The anterior coxse are generally obliquely ex- 

 serted ; but this is an inconstant character. 



In deciding whether a Cerambycid with finely faceted eyes 

 belongs to this group or not, the characters chiefly to be looked 

 to are (1) the volume of the lower lobe of the eyes and the 

 extent to which this has become frontal, (2) the presence of a 

 distinct prostemal process, and (3) the prolongation of the head 

 below the eyes. Species in which the eyes are lateral and the 

 prostemal process narrow or obsolete are either NecydaliyicB or 

 Molorchince. The abbreviation of the elytra is not an essential 

 character. The triangular shape of the metasternal epistema 

 ought, however, I think, to be considered a sine qua non ; this 

 woidd exclude Tricliomesia^ an Australian genus which La- 

 cordaire places in the "groupe," and which is the only form in 

 it not belonging to Tropical America. 



Although so forbidding to the pure systematist, the Rhino- 

 traginm are full of interest to the general naturalist, on account 



