RHYNCHOPHORA. 



189 



Division 6. RHYNCHOPHORA. 



The chief characters of the Rhy^chophora are as follows : — 

 Head usually prolonged into a rostrum or snout of varying length 

 and thickness ; antennae straight, or geniculate, with a longer or 

 shorter scape, and with a more or less distinct club ; gular sutures 

 not traceable ; side sutures of the presternum obsolete ; tarsi 

 apparently tetramerous, but really 5-jointed, the first three joints 

 being always present (the third, as a rule, more or less strongly 

 bilobed), the fourth, except in very rare instances (e. g. Dryoph- 

 thorus), being rudimentary, and the last joint being very rarely 

 absent (as in Anoplus). The testes are follicular, the follicles 

 being roundish and stalked ; six Malpighian tubes are present ; 

 the elytra are usually more or less distinctly striate, and the 

 venter is composed of five segments, of which the first two are, 

 as a rule, connate and immoveable. The wing-venation breaks 

 down in this group, as the species in this respect incline both to 

 Type I and Type II (see p. 40). 



The larvae, as a rule, are maggots quite destitute of legs, but 

 these are present in the Brenthibj?: and also in certain Anthri- 

 biDjE. The Scolytidje and Anthrieid.i; have no distinct rostrum, 

 and in Platypus the legs are slender, and quite different from the 

 normal Curculionid type. As a rule, however, the above charac- 

 teristics of the group hold good. 



The theory of Leconte and Horn that the Rhykchophora are 

 the lowest type of Coleoptera appears to be now regarded as quite 

 untenable ; the concentration of the nervous system alone suffices 

 to prove that the group is a long way up the scale, though it is 

 open to question whether Lameere is right in his account of their 

 evolution. He regards the Nemo^tchen^e (Rhinomacerin^e), 

 (which he considers to have had a common ancestor with the 

 Laeiidje or to have been descended directly from primitive 

 Lariid^e) as the common ancestor, " from which we pass to forms 

 without labrum and with rigid maxillary palpi represented at first 

 by divers types of Orthocera, such as the Atteeabin^e ; from 

 primitive Orthocera the general stock of the CiiRCUBKXNiBiE 

 separated itself off, and under these may be classed the Erirrhi- 

 neoe ; from these last there detached themselves in different 

 directions the Otiorrhynchiioe, the Ceuthorrhynchit^e, and 

 the Caba^eri^^e, forming three superior types."' The Scobytidje, 

 moreover, are regarded as merely a specialised form of the 

 Cabakdrisue, and not as a separate family. 



A very large number of species are contained in the series ; 

 from 15,000 to 20,000 are now known, and they will probably in 

 time be found to amount to more than ten times this number, as 

 they have been comparatively neglected, and in any faunistic 

 work on the group the number of new species is very great. 

 Mr. Champion has recently been working out the Central 

 American species in the " Biologia Centrali- Americana," and 



