84 THE VOYAGE OF H.M.S. CHALLENGER. 



able concentric lamellse which are peculiarly curled upwards, strongly Urate, and minutely 

 cancellated on the lower side. In addition to these lamellae there are finer concentric lirse 

 between, usually one in each interstice. Beside these the whole surface is densely and 

 minutely sculptured with microscopic radiating thread-like lines, which are not so 

 apparent as those upon the lamellae. The hinge is composed of two minute cardinal teeth 

 in each valve and two moderately developed laterals, whereof the posterior is rather more 

 remote from the apex of the umbones than the anterior. The internal cartilage is long 

 and narrow, and the external ligament, which is somewhat shorter, is slight. The interior 

 of the valves is white, and exhibits a number of faint radiating depressions, one of them, 

 which crosses the anterior muscular scar, and is, as it were, a continuatioli of the pallial 

 line, being particularly noticeable. The pallial sinus is directed upwards, obtuse at the 

 extremity, and reaches about half-way across the valves. The specimen obtained by the 

 Challenger is rather larger than the type described by A. Adams, being 66 mm. long, 

 52 high, and 25 in diameter. 



Semele ohliqua (Wood), juv. 



Tellina ohliqua, Wood, Gen. Conch., p. 152, pi. xli. figs. 4, 5. 

 Amphklesma ohliqua, Eeeve, Conch. Icon., vol. viii. pi. i. figs. 5a-h. 

 Amphidesma variegata, Lamarck, Anim. s. Vert., ed. 2, vol. vi. p. 126. 

 Davila variegata, Clieuu, Man. Conch., vol. ii. p. 80, fig. 346. 



Habitat. — Station 122, off Pernambuco, Brazil, in 350 fathoms; red mud. 



Only a single young specimen half an inch in length was obtained. It is whitish, 

 Ijlotched on the dorsal margin and towards the beaks with pinkish-red, and speckled in 

 the same region with opaque white. The great depth at which this shell lived probably 

 will account for the paleness of its colouring, which is much more vivid in all the other 

 specimens that I have seen. 



Semele infans, n. sp. (PI. V. figs. l-\h). 



Testa parva, oblique rotundato-subtrigonalis, ina^quilateralis, alba, nitida, iucrementi 

 lineis sculpta, lunula distincta, lanceolata antice instructa. Umbones acuti, post medium 

 siti, anticam partem versus inclinati. Margo dorsalis posticus valde descendens, arcuatus, 

 anterior prope umbones concaviusculus, deinde excurvatus, ventralis late rotundatus, 

 postice subsinuatus. Dentes cardinales duo iu valva dextra, uuus in valva altera. Fossae 

 laterales valvae dextrae magnae, latae, usque ad umbonem utrinque extensEe. 



The shell is minute, longer than high, thin, glossy, and sculptured with fine yet 

 distinct lines of growth. It is of a roundish subtriangular form and inequilateral, the 

 anterior end being the longer and regularly sharply curved, whilst tlie opposite side 



