Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.1): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

560 CATALOGUE — 'SHELLS. 18. TerebhAtula FLEXrOSA. T. testd rotundato-cordatd, gibbd, sub-fused, hngitudinaliter creber- rinie sulcatd; viargine valde jicxuoso ; long.l^; lal. 1^ jmuIo minus; poll. Habitat in freto Magellanico (Port Famine). Mus. Brit., nost., Brod. This shell, which was dredged up from deep water in the bay of Port Famine, attached to stones, is not a common shell in the Strait. 19. Tekebkatula Sowerbii. T. testd subrotundd, planiusculd, subjuscd, hngitudinaliter radiatim trayisversim substriatd, rnedio superne depressd, infra convexd, sub- glabrd; 7nargine utrinque erenulato, medio glabra ; long, l^'jy ; lat. -^1^ paulo plus; alt. J| j)oll. Habitat in freto Magellanieo. Mus. nost., Geo. Sorverby. 20. Chiton setiger. C. testd ovali, antice subattenuatd ; valvis subdcntatis, tenuiter con- centrice striatis, anticd lO-radiald, posticd laivi, jyarvuld ; arcis lateralibus striis duabus elevatis marginalibus ; ligamento mar- ginali leevigato, setigero; long. 2^; lat. 1§; poll. Habitat ad oras insuke Tierra del Fuego ct in freto Magellanico. Mus. Brit., nost., Brod. Shell ovate, rather attenuated towards the anterior end, generally of a light blue-green colour, variegated with markings of dark slate. Valves slightly beaked with minute concentric striae, the lateral compartments with two marginal ridges, whicli in some specimens are granulose, in others smooth. The anterior valve has eight, besides two marginal, ridges of the same character ; the pos- terior valve is very small and smooth. Border coriaceous, and set with bristles produced from three rows of tufts or pores. In some of the specimens in my possession the bristles are rubbed off. The shell is found in all parts of the shores of Tierra del Fuego, particularly on its seaward coast, and the western parts of the Strait of Magalhaens. 21. Chiton Bowenii. C. testd oblongo-ovatd, castaneo-rifd; dorso elevato; valvis subden- tatis, sublcEvibus concentrice tenuiter striatis; areis lateralibus radiatim sulcatis ; ligamento marginali granuloso, nigro; lo'ig. 3| ; lat. 1| ; poll.