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



Tellina ( ?) languida, n. sj). (PI. IV. figs. 8-8?^). 



Testa parva, tenuis, alba, pellucide zonata, nitida, incrementi lineis tenuissime striata, 

 insequilateralis, ovata, postice acuminata. Margo dorsi auticus vix obliquus, levissime 

 convexus, posticus valde declivis, rectilinearis. Ventris margo antice arcuatus, postice 

 lente vix arcuatim adscendens. Umbones parvi, acuti, prominuli, postmediaui. Dentes 

 cardinales duo in utraque valva, quorum unus triangularis, bifidus. Dentes et fossae 

 laterales graciles, remoti. Ligamentum parvum, partim internum. Sinus pallii per- 

 magnum, profundum. 



This species is very like Tellina casta with regard to sculpture, colour, and the 

 character of the cardinal teeth and ligament. It is, however, of a different form. It is 

 decidedly more inequilateral, has the anterior end higher and more broadly rounded, the 

 dorsal slope on that side less straight, and the posterior end more acuminate. The lateral 

 teeth are also more remote and less pronounced. It is of an irregular ovate form, 

 narrowed and pointed behind. It is considerably inequilateral, glossy, finely concentri- 

 cally striated, moderately convex, white varied with a few semitransparent zones. The 

 front dorsal margin is a very little convex and only slightly oblique, the j)osterior being 

 almost rectilinear and very slanting. The lower outline is broadly arcuate, more rajiidly 

 upcurving in front than posteriorly, where the ascent is straightish, scarcely incurved. 

 The umbones are small, acute, a little elevated and worn at the extreme tip. The pallial 

 sinus is very wide and deep, and extends three-fourths of the way across the valves. 

 There are two cardinal 'teeth in each valve, whereof the posterior in the right and the 

 anterior in the left are much stouter than the others, and liifid. 



Length 9 mm., height 7, diameter 4|^. 



Habitat. — Torres Strait, in 3 to 11 fathoms, and Flinders Passage, in 7 hithoms. 



Tellina ( ?) tenuilamellata, n. sp. (PL IV. figs. 9-9/>). 



Testa rotundata, asquilateralis, tenuis, semipellucida, alba, lineis ojjacis albis radian- 

 tibus tenuissimis disjunctis oruata, antice regulariter curvata, postice paulo angustior, 

 lamellis angustissimis concentricis instructa. Margo dorsi utrinque declivis, leviterque 

 convexus. Margo ventralis late arcuatus, posterius vix sinuatus. Umbones ad apicem 

 plerumque erosi, aliquanto prominentes. Dentes cardinales duo in utraque valva, postice 

 valvae dextrse valde bifido. Laterales conspicui, anteriori cardinalibus subapproximato. 



This species is a little longer than high, rather roundish, well rounded in front and 

 indistinctly pointed behind. It is very thin, fragile, and semitransparent, so that the 

 external sculpture and markings are seen through on the inner surface. It is almost 

 equilateral, whitish, or faintly tinged with yellow, ornamented with excessively fine 



