-MR. CURTIS ON HYPOCEPHALUS, A GENUS OF COLEOPTERA. 235 
that I was led to make some changes which I shall correct on the first opportunity. Indeed 
if we were to reject the form of the feet in the Coleoptera, disregarding the number of 
the joints, the Heteromera might be distributed throughout the entire mass. 
I must not, however, be misunderstood regarding the value of the structure of the 
mouth in the formation of systems, for although it may be subject to great modifications, 
and depart from the typical forms, like the changes in the tarsi, such anomalies are perhaps 
confined to the minuter members of a family, and a comparison of the trophi is unques- 
tionably of the greatest importance in arriving at the true affinities of insects. As our 
materials multiply our knowledge advances, and changes become necessary and unavoid- 
able, but let them be made on substantial grounds, not losing sight of the first principles 
of true affinity. 
I trust that those from whom I differ in opinion will be assured, that it is from no love 
of opposition that I have ventured upon this difficult subject, but with the sole desire of 
arriving at the truth, and to assist in fixing our Systems on some firm basis, generally 
understood, and universally to be adopted, so that we may no longer be tossed to and fro, 
as we are at present; every new work, unscrupulously changing, sometimes entirely 
reversing or disregarding, the labours of the most profound and learned men of science, 
that have adorned the pages of Natural History. 
EXPLANATION OF THE PLATE. 
TAB. XXV. 
Fig. 1. exhibits the under side of Hypocephalus armatus, mas? a little larger than Mr. Turner's specimen ; 
a. the antenne; m. the mandibles ; p. the palpi, the central pair being the labial, inserted at the 
margin of the trilobed menfum. Between the base of the head and the antepectus is shown the 
large membranous triangular cavity, enclosed on the sides by a series of broad teeth (s). At the 
base are inserted the 1st pair of legs, with short, slightly dilated tarsi; a lobe passing between 
the coxæ, dilated at the apex, keeled down the middle (a. p). The ample postpectus follows 
(p. p), near the base of which the 2nd pair of legs is inserted, with much longer tarsi, and at 
the hinder margin the 3rd pair of legs, with enormous thighs, curved tbis, and perfect speci- 
mens exhibit 5-jointed tarsi similar to the 2nd pair, but the basal joint 1s shorter. Fig. à. is the 
small attenuated abdomen. 
Fig. 2. Upper side of head, showing the spreading 
lobes of the head; m. the mandibles; e. the eyes. 
Fig. 3. The insect in profile ; a. the antenna; l lateral lobes of the head ; m. the mandibles; p. the palpi; 
e. the eye; s. the serrated or toothed margin of the antepectus. 
Fig. 4. Antenna magnified. 
Fig. 4*. The trilobed broad mentum ; p. the triarticulate palpus. 
Fig. 5. Four basal joints of the anterior tarsi magnified. 
as I am able, I have added figures of the trophi, &c. of Cyr- 
lobes at the base (b); a. basal joint of antenna ; l. lateral 
To illustrate this subject as far 
tognathus rostratus, Fabr. cd 
