Scarites (a genus of the Carabidæ), there also the mandibles are greatly developed (in proportion, almost as much as in the Lucanidæ), & in size eminently variable.²

And, as I suppose the principle is the same whether the organs be above or below the medium standard of development, we might perhaps cite the wing-cases (elytra) of Melöe as a case in point. These are unusually reduced in dimensions (for the Coleopterous type), scarcely covering two-thirds of the abdomen; & they are, in some of the species, very inconstant in size.—

The connateness of elytra (as having merely a character, & not an organ) will not perhaps suit you.— otherwise I might mention that the only Harpalus (I believe) on record in which the wing-cases are ever joined is the H. vividus of the Madeiran Islands (opus diab. p.p. 56, 57);³ but that character (anomalous as it is) does not always occur in that species,—the elytra being sometimes connected, sometimes sub-connected, & occasionally almost (if not entirely) free.—⁴

Such are a few facts which strike me primâ facie, from very ordinary & commonplace material. With the extravagancies of Nature (such as the tropics may produce) I have nothing to do; but, if this principle be an universal one, an examination of the Leaf-insects & (for instance) those remarkable Homopterous creatures in which the thoracic projections take every conceivable form, might perhaps throw some additional light upon it.—

The basal joint of the feet of some of the Madeiran Tarphii is wonderfully developed into an elongated spine; but I have not yet observed any variability in this,—unless indeed (as is not likely) I have been mistaken in regarding it as sexual.

I must however cease, for Time fails, & moreover I am not in great condition for either thought or work. Good luck to the Helices: may they live,—tho’ not, I trust, in salt-water.⁵

Yours very sincerely | T V Wollaston.