17. Mytilus erosus, Lam. Hist. 6 pt. 1 120.
This sh.e.l.l was described by Lamarck from some New Holland specimens, that were probably collected by Peron in Baudin"s voyage. It is remarkable for being very thick and solid, and of a fine dark colour, with only a narrow white band on the anterior basal edge. The edge is crenated, and the muscular impressions are very distinct, and raised above the surface, particularly that on the anterior valve, which is both pellucid and tubercular.
18. Modiola (Tulipa ?) australis, n.o.b.
Modiola tulipa, var. 1. Lam. Hist. 6 pt. 1 111.
This Australian species will most probably prove to be distinct from the American kind; but the specimen before me does not afford sufficient materials to separate it, since there is only one water-worn valve in the collection. It is not so distinctly rayed as M. tulipa, and the inside is entirely of a brilliant pearly purple, except near the anterior basal edge.
19. Lithophagus caudatus, n.o.b.
Modiola caudigera, Lam. Hist. 6 pt. 1 116.
Icon. Ency. Meth. plate 221. f. 8. a, b.
20. Meleagrina albida, var. a. Lam. Hist. 6 pt. 1 152.
This appears to be a distinct species from those found in the Gulf of Mexico and the West Indies, but the difference is not easy to describe.
The specimens before me, which are small, differ materially from some of the same size among the American species. The outside is of a dull greenish-purple colour, with a few distant membranaceous laminae which are only slightly lobed, and not extended into long processes like those of Avicula radiata (Zool. Misc. 1. t. 43.) which is the young of the American kind. The internal pearly coat has a bright yellow tinge.
21. Spondylus radians ? Lam. Hist. 6 pt. 1 192.
Icon. Chemn. Conch. 7 t. 45. f. 469. 470. Ency. Meth. plate 191. f. 5.
22. Pecten maximus ? Lam. Hist. 6 pt. 1 163.
Ostrea maxima, Gmel. Syst. Nat. 1 3315.
Icon. Chemn. Conch. 7 t. 60. f. 585. Ency. Meth. plate 209. f. 1. a, b.
The sh.e.l.l before me is probably distinct from the above species, but is too much worn down to be separated from it; in its present state it seems to agree tolerably well with the species to which it has been referred.
23. Pecten asperrimus, Lam. Hist. 6 pt. 1 174.
This beautiful species was originally found by MM. Peron and Lesueur on the coast of Van Diemen"s Land.
24. Lima minuta (n.s.)
Testa ovato-oblonga valde tumida clausa radiatim costata, costis transverse costato-striatis, auriculis minutis, margine crenato.
This sh.e.l.l, which was brought up by the deep sea sounding-lead, being only one-sixth of an inch long, and one-fourth high, is the smallest species of the genus. It is white, ovate, oblong, turned and closed at the ends; the surface is deeply radiately ribbed; the ribs are concentrically rib-striated, which gives their sides a denticulated appearance; the edge is crenulated, and the umbones are acute, a small distance apart, and nearly in the centre of the hinge margin, which is straight.
25. Pinna dolabrata, Lam. Hist. 6 pt. 1 133.
Pinna bicolor, Chemn. Conch. Cab. t. 90. f. 234.
Icon. Chemn. 8 t. 90. f. 780 ?
The sh.e.l.l, figured by Chemnitz, appears to be a variety of this species with the anterior end uncurved, which has most probably been caused by some injury on the anterior basal edge.
The species is peculiar for its yellow pearly internal coat, and purplish rays.
2. COCHLEOPHORA.
26. Trochus caerulescens. Lam. Hist. 7 18.
Icon. Ency. Meth. plate 444. f. 2. a, b.
Inhab. South-west Coast.
Lamarck describes this sh.e.l.l from a specimen found by Peron.
27. Trochus noduliferus, Lam. Hist. 7 18.
28. Monodonta conica (n.s.)
Testa conica, acuta, imperforata, spiraliter striflto-costata, rufa; costis subtuberculatis, albo-nigro-articulatis; apertura sulcata.
Inhab. -- Mus. Brit.
Sh.e.l.l conical, axis longer than the diameter, the whorl flattened with six spiral raised substriae, which are transversely divided into blackish purple beads with white inters.p.a.ces, the apex rather acute; the base, rather convex, axis imperforated; the aperture subquadrangular, inside furrowed; the base of the columella lip with a prominent tooth and distinct groove behind it, the upper part rugose; axis eight-twelfths, diameter six-twelfths of an inch. This sh.e.l.l does not appear to be uncommon on the coast of Australia.
29. Monodonta uranulata (n.s.)
Testa depresso-conica, umbilicata, purpurea, albomarmorata, spiraliter papillata; papillis quadri-seriatis, umbilico laevi; infima facie papillata, apertura sulcata.
Inhab. Mus. Brit.
Sh.e.l.l rather depressed, conical, purple variegated with white, generally concentrically wrinkled, and ornamented with granulated spiral ribs, the ribs of the upper part of the last, and of all the other whorls rather distant, and forming four series; those of the under part rather closer, and smaller. The axis unbilicated, smooth, the aperture roundish, the outer lips furrowed, the columella lip smooth with a groove at its base, axis four-twelfths, diameter five-twelfths of an inch.
30. Monodonta denticulata (n.s.) Testa depresso-conica, umbilicata, rufa, nigro punctata, spiraliter sulcata, subgranulata, umbilico extus crenato.
Inhab. -- Mus. Brit.
Sh.e.l.l depressed, conical, pale reddish, ornamented with rows of white and brown spots, spirally grooved, ribs slightly granulated; the sutures distinct, impressed, the lower part of the last whorl nearly smooth, the umbilicus white, smooth inside, the edge furnished with a series of granules. The mouth subquadrangular, outer lip crenulated at the edge, the columella lip smooth, with a large tooth at the inside, and a little roughness on the outer side; axis three-tenths, diameter five-twelfths of an inch.
31. Monodonta constricta, Lam. Hist. 7 36.
32. Monodonta rudis (n.s.)
Testa ovato-conica imperforata ulbido-purpurea rudis cra.s.sa, labro duplicato, extus albido viridi, intus subsulcato, albo.
Inhab. -- Mus. Brit.
Sh.e.l.l ovate, conical, imperfurated, rough, pearly, concentrically striated, whitish-brown; when worn or where eroded, purple; the whorls convex, suture distinct, sometimes occupying an impressed line on the lower whorl; the base rather convex, the aperture roundish, the axis (imperforate) covered with a white callus, which leaves a slight concavity over its end; the outer lip of three colours, the outer part purple or green and white, the middle pearly, and the inner opaque, white, and furrowed; the surface of the lower part of the last whorl is frequently worn away just opposite the mouth, so as to leave a purple spot.
33. Rissoa clathrata (n.s.)
Testa subglobosa, subimperforata, alba, solida, spiraliter et concentrice costata; apertura suborbiculari, sutura impressa.
Sh.e.l.l nearly globular, spire conical, upper whorls with three, lower with seven distinct, large, rather separate, much raised, spiral ribs, and numerous acute transverse ribs, which form an acute tubercle where it crosses the spiral ridges, the suture deeply impressed, very distinct, the aperture nearly orbicular, the outer lip denticulated on its outer edge, inner lip smooth, column without any perforation, only a slight linear cavity behind the inner lip, axis and diameter each one-sixth of an inch.
This sh.e.l.l is allied to Littorina muricata (Turbo muricata, Lin.) in its general form and the shape of its umbilicus, but is white and ribbed like Rissoa cimex (Turbo cimex, Lin.) R. calathriscus, the Turbo calathriscus of Montague.
34. Solarium biangulatum (n.s.)
Testa orbiculato-conica subdepressa albida spiraliter sub-striata rufo variegata, anfractibus biangulatis supra planis infra convexis, umbilico pervio edentulo.