414 Suarp— On New Zealand Coleoptera. 
Fam. CURCULIONIDZ:. 
OvrIORHYNCHINI. 
The classification of this difficult group of weevils has been much improved 
during the last few years; it is considered by Leconte and Horn as a separate 
family of Rhynchophora. It is, however, still very difficult to determine in the 
case of certain weevils whether they belong to this group or not; it is defined 
as consisting of such Rhynchophora as possess in.the pupal condition and im- 
mediately on emerging therefrom, supplementary mandibles aflixed to the true 
mandibles, deciduous and usually leaving a scar on the spot from which they 
were detached. This scar is very conspicuous in the case of the large majority 
of the genera of Otiorhynchini, but in some it can scarcely be detected, and 
then it can only be by inference that the genus can be determined as belonging 
to the family, it being rarely possible to observe the creature immediately on 
its emerging from the pupal condition; fortunately it frequently happens that 
one or both of the deciduous mandibles are preserved rather longer than usual, 
and this is of great assistance in these difficult cases. The New Zealand genus 
Rhadinosomus is one of the uncertain forms; it was placed by Lacordaire 
in the Otiorhynchide, but I am not able to find any trace of the mandibular 
scar, and I have not, therefore, included it in the following table of the New 
Zealand genera of Otiorhynchini, though it is quite probable that observation 
may show that it ought to be so included. In the table the primary division 
adopted is that of Lacordaire, according to the presence or absence of an ocular 
lobe; only one of the New Zealand genera was known to Lacordaire, viz. 
Catoptes, and this he placed m the wrong division. Catoptes possesses an 
ocular lobe, though in only a rudimentary state; indeed Mr. Pascoe has re- 
characterized the genus, under the name of Irenimus, and correctly stated that 
it possesses an ocular lobe. For the information of New Zealand entomologists 
I may say that the ocular lobe, when rudimentary, consists merely of a slight 
projection of the side of the thorax towards the eye; but it is nearly always 
accompanied by two correlative marks, viz. an emargination of the front of 
the prosternum, and a change in the form of the eye, the rule being, that m 
species with an ocular lobe the eye is increased in diameter from above to 
below, whereas, when there is no ocular lobe, the tendency is for the eye to 
increase in the transverse diameter that is to extend towards the tip of the 
rostrum. It is especially necessary to remember this in examining these New 
Zealand insects, because in them the ocular lobe itself is never extremely 
developed, and is frequently quite rudimentary. The opening of the corbels 
or tips of the hind tibie is also a very important character in the present 
classification of the family, and this also in the case of the New Zealand insects 
is frequently exhibited in only a rudimentary form. White’s genus, Platyomida, 
