EEPORT OX THE LAMELLIBRANCHIATA. 105 



Tellina [Arcopagia) elegant issima, n. sp. (PI. IV. figs.' 3-36). 



Testa tenuis, albida vel pallide flavescens, ad umbones opaco-albo tincta, paulo 

 infequilateralis, transversim ovata, antice valde rotundata, postice angustior, acutior. 

 Margo dorsi anticus leviter declivis et arcuatus, posticus paululum brevior, vix magis 

 obliquus, subrectus. Margo ventris convexus, posterius baud flexuosus. Valvse leviter 

 convexse, liris numerosis radiantilius tenuibus, alternatim majoribus, aliisque concentricis 

 graciUoribus concinne sculpta3 ; lunula parva, profunda, laneeolata, sublsevis ; area valva3 

 sinistr^e Isevis, concava. Dentes cardinales lateralesque prominentes, tenues. 



This species is very fragile, and so thin that the external reticulation of the surface is 

 visible within the valves. It is a little inequilateral, broader and more rounded in front 

 than behind, whitish or very pale }ellowish excepting the tips of the umbones, which are 

 opaque white. The dorsal margin is almost equally sloping on both sides, scarcely curved 

 anteriorly, and almost straight behind. The lower or ventral outline is well curved, more 

 gently ascending posteriorly than in front, and not sinuated. The surface of the valves is 

 ornamented with a very fine network of delicate radiating thread-like lirae, which are 

 generally alternately finer and coarser and crossed by still finer concentric elevated lines, the 

 points of contact being a little thickened. The dentition of the hinge is almost precisely 

 the same as in Tellina pretiosa, Deshayes, and the pallial scar is also very similar. 



Length 15^ mm., height 12, diameter G. 



Habitat. — ^Torres Strait, in 3 to 11 fathoms. 



From Tellina pretiosa of Deshayes, its nearest ally, this species is distinguished l)y 

 being less acuminate posteriorly, more finely cancellated, and more inequilateral. The 

 radiating costellse in the species under consideration are more numerous, but the con- 

 centric ones, which are not elevated into scale-like projections on crossing the others, are 

 fewer than in Deshayes' shell. 



Tellina ( ?) donacina, Linn^. 



Tellina donacina, Linne, Syst. jS^at., eJ. 12, p. 1118. 



Tellina donacina, Montagu, Test. Brit., pi. xxvii. fig. 3. 



Tellina donacina, Wood, Gen. Couch., pi. xlv. fig. 5. 



Tellina donacina, Pliilippi, Enum. Moll. Sicil., vol. i. p. 24. 



Tellina donacina, Hanley, in Sowerby's Thesavu'us, vol. i. p. 232, i)l. Ivi. fig. 12, and pi. Ixvi. 



fig. 259. 

 Tellina donacina, Forbes and Hanley, Brit. Moll, vol. i. p. 292, pi. xx. figs. 3-4, PI. K, fig. i. 

 Tellina donacina, Jeffreys, Brit. Conch., vol. ii. p. 386, and vol. v. p. 187, pi. xli. fig. 4. 

 Tellina donaiina, Sowerby, in Eeeve's Conch. Icon., vol. xvii. pi. x. fig. 43. 

 Tellina donacina, Romer, Conch. -Cab., ed. 2, p. 26, pi. ix. figs. 8-12. 

 Tellina donacina, Bertin, Nouv. Arch. Mus. Paris, 1878, vol. i. p. 261. 



Habitat. — Station 75, ofi" Fayal, Azores, in 450 fathoms ; volcanic mud. 



(7.OOU CHALL. EXP. PART XXXV. — 1885.) Mm 14 



