Zoological Illustrations Volume Iii Part 15

I have little doubt that this sh.e.l.l is a smooth variety of the _Pinna bullata_ of Gmelin, and the _P. marginata_ of Lamarck; both these authors refer to the same figure in Gualtieri, but both also have overlooked that of Chemnitz, above quoted, as well as Knorr's, which latter, although it represents the sh.e.l.l nearly smooth (similar to that here figured), I apprehend is only a variety. No doubt therefore having existed as to Gmelin's _bullata_, M. Lamarck had no plea for altering its specific name to _marginata_. I have consequently recorded it under Gmelin's name.

The Pinnae are rather numerous, although many of the species remain in obscurity; they attach themselves to rocks, deep in the sea, by a silky _byssus_. It has been commonly stated, that gloves and stockings are fabricated in the Mediterranean from this byssus, as articles of commerce; such, however, is not now the case; though articles, so fabricated, are sometimes shown in Naples and Sicily as subjects of curiosity.

Pinna bullata is, I believe, found in the West Indies. The vaulted spires on this and other species, easily fall off; and become, therefore, a very uncertain specific character.

Pl. 159

[Ill.u.s.tration]

SATYRUS argenteus.

GENERIC CHARACTER.

_Antennae mediocres, clavo elongato, gracili. Palpi porrecti, compressi, vix recurvi, remoti, pilis ciliatis, longis, hirsutissimi; articulo ultimo elongato, nudo, gracili, acuto. Alae posticae orbiculares, integrae, rar dentatae._

Antennae moderate, the club lengthened and slender. Palpi porrected, compressed, slightly recurved, remote, with long ciliated hairs; the last joints long, naked, slender, acute. Posterior wings...o...b..cular, entire, rarely dentated.

Generic Types. _Pap. Hyperanthus_, _Galathea_, _Semele_, _&c._ Lin.

SPECIFIC CHARACTER.

_S. alis fuscis; posticarum disco supra flavescente, maculis 2 fuscis fucato, infra albente, margine postico fulvo, maculis 2 atris guttisque 7-8 argenteis ornato._

Wings brown; posterior above with a yellowish disk and two brown spots, beneath whitish, the hind margin fulvous, with two black spots and 7-8 silver dots.

Without being ornamented by rich or vivid colouring, this is, nevertheless, one of the most chastely beautiful little b.u.t.terflies found in Brazil. I met with it very plentifully in a small wood not far distant from Cash.o.e.ra, on the western extremity of St. Salvador's bay: to this particular spot it seemed confined, for I never saw a single specimen in any other part of Brazil.

No colouring can imitate the richness of the silvery spots on the under wings, which appear embossed, or as if solid drops of silver had fallen on the insect when it first emerged into life. The two s.e.xes are perfectly similar.

The insects of this genus are usually brown, with dark or paler shadings, and eye-like spots on their upper or under wings. They princ.i.p.ally inhabit the woods of tropical regions, and the hedge sides and lanes of European countries; this circ.u.mstance probably induced Latreille to change their name from _Hipparchia_ (Fabricius) to _Satyrus_; which, although an innovation on the rules of nomenclature, may in this instance be allowed.

Pl. 160

[Ill.u.s.tration]

ANODON purpurascens,

_Purple Anodon, or Horse Mussel._

GENERIC CHARACTER.--See Pl. 96.

SPECIFIC CHARACTER.

_A. testa transversim oblonga, cra.s.sa, depressa, intus purpurascente, lamina cardinali cra.s.sa, truncata, dente lamellari in utraque valva supposito; umbonibus retusis._

Sh.e.l.l transversely oblong, thick, depressed, within purple; hinge plate thick, truncate, with an obsolete lamellar tooth in each valve; umbones retuse.

This is an entirely new and very rare sh.e.l.l, remarkable for its shape and internal colour; it is also highly interesting, as exhibiting the generic characters of _Anodon_, blended (in some degree) with those of _Unio_: according to the principles of Lamarck, it might therefore be made into a genus; but I feel convinced too much importance has already been attached by that naturalist and his followers to the hinge of bivalve sh.e.l.ls; and that the nomenclature of the science is burthened with genera, trivial in themselves, bewildering to the scientific, and unintelligible to the student.

From having paid some attention to the Fluviatile Bivalves, and possessing a most extensive collection of specimens, I am clearly of opinion that no permanent characters will be found sufficient to retain either the genera _Dipsas_ (Leach), _Hyria_ (Lamarck), or _Alasmodonta_ of Say, much less that of _Damaris_ (Leach), and another, whose name I forget, made by Dr.

Turton from the same sh.e.l.l as Leach's _Damaris_, viz. Mya Margaritifera of Linnaeus. In fact, the line of demarcation between Unio and Anodon appears to rest on the first possessing cardinal teeth, and the latter having none.

I have several valves (in different stages of growth), and one perfect specimen of this sh.e.l.l; they were sent to me from the back settlements of North America.

Pl. 161

[Ill.u.s.tration]

VOLUTA punctata,

_Red-dotted Volute._

GENERIC CHARACTER.

_Testa ovata. Spira apertura brevior, apice papillari. Basis truncata, emarginata. Columella plicata, plicis inferioribus majoribus._

Sh.e.l.l ovate. Spire shorter than the aperture, the tip papillary. Base truncated, emarginate. Pillar plaited, the inferior plaits generally largest.

Generic Types. _Volutae Olla_, _Imperialis_, _Pacifica_, _&c._

SPECIFIC CHARACTER.

_V. testa ovata, subfusiformi, tuberculata, pallide rubella fasciis 2 maculatis, rubris, punctis minutis interstinctis; columella 4 plicata._