Zoological Illustrations Volume I Part 13

The celebrated Latreille, the father of modern Entomology, has well observed, that the immense number of insects crowded together in the genus _Hesperia_ contain many natural genera, but which the paucity of species generally found in cabinets prevents us from discriminating. Having for a long time paid attention to this family, and possessing near 300 species in my own cabinet, I have had the opportunity of attempting their elucidation; and the above generic character is applied to those insects only which I propose considering genuine species of the genus _Hesperia_, and which will comprise near 170 species.

I have named this new, undescribed and very rare insect, in honour of my esteemed friend A. H. Haworth, Esq. F.L.S., &c., well known by the benefits his writings have conferred on the sister sciences of entomology and botany. The only two insects I ever saw of this species I captured in the southern part of Brazil.

Pl. 29

[Ill.u.s.tration]

MITRA cancellata.

_Basket Mitre_--upper figure.

GENERIC CHARACTER.--See Pl. 23.

SPECIFIC CHARACTER.

_M. (Div. 2.) testa fusiformi, cancellata; striis longitudinalibus incra.s.satis, spira aperturaque aequalibus; columella 5-plicata; spira sublaevi._

Sh.e.l.l fusiform, cancellated, the longitudinal striae thickened; spire and aperture of equal length; pillar five-plaited; spire nearly smooth.

Another undescribed species of this elegant family, and of great rarity, in the private collection of Mr. G. Humfreys. The whole of the body whorl and commencement of the spire is cancellated. The longitudinal striae are crowded, thickened, and slightly elevated, giving a crenated appearance to the suture: the transverse striae slender, and filling up the interstices.

The spire is nearly smooth and a little bent: the ground colour very light orange, with three darker interrupted bands on the body: whorl separated by two slender lines of the same colour; the spiral whorls have only two bands and a line between; the upper margins slightly compressed on the suture; the outer lip within smooth.

MITRA rigida.

_Ribbed Mitre__--middle figures._

SPECIFIC CHARACTER.

_M. testa costis longitudinalibus, elevatis, linearibus, integris, interst.i.tiis laevibus ad basin granulatis; spira producta; columella 4-plicata; apertura brevi._

Sh.e.l.l with elevated, longitudinal, obtuse, entire ribs, the interstices smooth, the base granulated; spire lengthened; pillar four-plaited; aperture short.

Equally rare, and from the same collection as the preceding. In habit it approaches nearest to _M. exasperata_ of Chemnitz, but has not the ribs angulated or their interstices striated, and is much more narrowed at the base than in that sh.e.l.l, which I have seen: the outer lip is also smooth; the inside strongly striated. This sh.e.l.l was formerly in the collection of Mr. Keate, the elegant author of the "Sketches from Nature."

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[Ill.u.s.tration]

ACHATINA marginata.

_Marginated Achatina._

GENERIC CHARACTER.

_Testa ovata, vel oblongo-ovata, spira elevata, apertura subovale.

Columella laevis, simplex, ad apicem truncata; labium externum tenue, internum inflexum integrum; umbilicus nullus._

Typus Genericus _Bulla Achatina_. Linn.

Sh.e.l.l ovate, or oblong-ovate; spire elevated; mouth nearly oval.

Columella smooth, simple, truncated. Outer lip thin; inner lip entirely inflexed. Umbilicus none.

Generic Type _Bulla Achatina_. Linn.

SPECIFIC CHARACTER.

_A. testa ovato-oblonga, strigis inaequalibus ferrugineis; spira ad apicem obtusa, 5-voluta; sutura depressa linea sulcata marginali._

Sh.e.l.l ovate-oblong, with irregular ferrugineous stripes; spire obtuse at the top, of five volutions; the suture depressed, with a marginal indented line.

_Lister_ 579. _fig._ 34. _Gualt. pl._ 45. B. _Knorr_, _vol._ iv. _tab._ 24. 1. (badly coloured.)

The largest sh.e.l.ls. .h.i.therto discovered as inhabiting the dry land belong to this genus, inst.i.tuted by the celebrated Lamarck, but still divided by the strict followers of Linnaeus between the _Bullae_ and _Helices_, with a singular infelicity of even artificial arrangement. The simple characters peculiar in a greater or less degree to all, will readily distinguish them; and I apprehend most of the species of the first division (which includes the present) will be found to inhabit only the African continent, while _Bulla virginea_ and the smaller sh.e.l.ls placed in the second division are found princ.i.p.ally in the new world; where also two or three gigantic species of _Bulimus_ occupy the place of the larger African _Achatinae_.

Of these, the sh.e.l.l now figured is one of the rarest, and has. .h.i.therto been overlooked as a variety of the Linnaean _Bulla Achatina_; the colour of both is subject to much variation; but this will be found at best a most indecisive and vague character for specific distinction when unaccompanied by others more important and connected with the formation of sh.e.l.ls. I have therefore not hesitated in making this a distinct species, from having had the means of examining at different times near twenty specimens, all of which presented the following characters. Spire of five whorls, the last or terminal one very small and flattened; the apex obtuse; the suture depressed, as if flattened on the sh.e.l.l, and margined by one or sometimes two indented lines, parallel, and at the top of each whorl. In the colour of its mouth it varies in sometimes having a tinge of rose-colour at the base and top of the spire, but the mouth is more generally white. The body whorl is more or less ventricose; the outer lip is a little reflected, and the whole sh.e.l.l, when full grown, much thicker and heavier than any of the other species. The epidermis is yellowish-brown, beneath which the sh.e.l.l is nearly white, beautifully marked with broad remote stripes of chesnut, with others more slender (and sometimes broken into spots) between. I have another specimen which agrees tolerably with Lister's figure in being more than usually ventricose, and which I think is accidental. The only constant variety appears to be that figured by Knorr, ii. tab. 3. fig. 1. having the spire entirely rose-colour.

The marginal line and the correct number of whorls in the spire are well expressed in the figures of Lister, Gualtieri and Knorr. The first of these figures is accidentally more ventricose; the second, like all the other figures of Gualtieri, is defective at the apex; and Knorr's I suspect has been outrageously coloured from the real pink-mouthed _Achatina_.

It inhabits the coast of Guinea; and I am informed the animal is eaten by the natives.

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