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Show 1881.] THE SURVEY OF H.M.S. 'ALERT.' 41 Gould, and agrees exactly with the single shell above described. In assigning P. wardiana to Carpenter, and California as its locality, Sowerby has exhibited a great want of care. LORIPES PERTENUIS, sp. n. (Plate V. fig. 5.) Shell very thin, compressed, obliquely subcircular, white, inequilateral. Valves concentrically finely striated, with a shallow groove running from the umbo down to the posterior end, but at a very little distance from the dorsal margin, and with a second depression bordering the dorsal edge. Umbones acute, rather prominent, situated very much forward. Hinge absolutely toothless. Interior of valves exhibiting traces of iridescence. Width 10 millims., length 9, thickness 4|. Hab. Straits of Magellan. This species is remarkable for its extreme fragility and the shallow depressions down the posterior dorsal slope. KELLIA MAGELLANICA, sp. n. (Plate V. figs. 6-6 b.) Shell equivalve, subequilateral, white, covered with a yellowish-olive epidermis, for the most part worn off, of an ovate form, a trifle narrowing anteriorly, the outline being interrupted by the prominence of the umbones, rather ventricose. Sculpture consisting of rather coarse concentric lines of growth. Umbones rather acute and prominent, somewhat curved anteriorly. Interior of valves of a bluish white, except at the margin, where the epidermis is narrowly reflexed within. Hinge composed of two stout teeth in the right valve-one immediately beneath the umbo, and the second rather widely separated from it by the intervening cartilage. Also two teeth beneath the apex in the left valve, and a third corresponding to the second tooth in the other valve, also parted off from the others by the internal ligament. Scars and pallial line indistinct; the latter appears quite simple. Width 8 | millims., length 7\, thickness 5. Hab. Station 6. This species is very much like the British K. suborbicularis, yet on close investigation appears distinct. It is more solid, has a stouter epidermis, stronger teeth, and the form is not quite the same. K. bullata, Philippi, also a Magellan species, must be very nearly allied to the present; yet the form, as described in the ' Archiv fur Naturgeschichte,' appears to differ. K. magellanica is almost equilateral, whilst K. bullata is said to be " vorn weit langer als hinten." ASTARTE MAGELLANICA, Sp. 11. (Plate V. fig. 7.) Shell small, subequilateral, elevated, subpyriform, and not very tumid, concentrically sulcated; beaks prominent, acute, curving considerably anteriorly. Lunule indistinct. The dorsal slope on that side rather incurved, posterior one regularly curved, basal margin broadly arcuate. Concentric waves numerous, close-set, very fine upon the umbones, gradually increasing in stoutness, attenuating at the sides. Epidermis thin, greenish yellow. Interior |