Report on the zoological collections made in the Indo-Pacific Ocean ...

MOlLtrSCA. 99is partly enclosed when the valves are shut. Cardinal teeth two ineach valve, those of the right most prominent. Front dorsal marginof right valve narrowly grooved just within, simple in the left.Corselet linear. Posterior muscular impression rotund-pyriform,anterior more elongate. Pallial sinus moderate, extending forwardbeyond the middle of the valve. Length 19| millim., height 10,diam. 5.Hob. Prince of "Wales Channel, 9 fms.A very elongate narrow species, recalling to mind certain slenderforms of the geniis Donax.25. Tellina semen.Hanley, Thesaurus, vol. i. p. 249, pi. 56. fig. 8 ;(? Sowerby, Conch.Icon. vol. xvii. fig. 232, bad !).Hah. Thursday Island, Torres Straits, in 5-7 fms.Among the specimens from this locality is one of a purplish-rosetint, the rest being white like the type. The hinge of this speciesis composed of two cardinal teeth in the right valve (the posteriorone larger and bifid, with one lateral tooth on each side aud a gropvebetween it and the margin), and of a single bifid cardinal in the leftvalve with a marginal lateral tooth or prominence on each side. Thepallial sinus is very large, almost reaching to the anterior scar.The form of this species is very similar to that of T. obtusalis,Deshayes, which is the same as T. malaccana, Sowerby (Con. Icon,figs. 2Sla and 125). The posterior end, however, is not so obtuseand the form is not so like that of a Donax, In T. obtusalis theconcentric striae are rather coarser than in the present species, andbecome very much finer anteriorly, so that in that part the shell ismore glossy and comparatively smooth, which is not the case inT. semen. Another form, T. semitecta, Sowerby, from New SouthWales, is very closely related to the present species, and is mainlydistinguished by its rather more elongate form, and finer aud lesselevated sculpture at the hinder extremity.26. Syndosmya elliptica. (Plate VII. figs. C, C 1.)Tellina elliptica, Soioerhy, Conch. Icon. fig. 223 (bad!).Hub. Port Jackson (Angas and Coppinger).The type and a second specimen of this sjiecies were presented tothe British Museum by Mr. Angas in 1871. Neither of these nor athird collected by Dr. Coppinger exhibit the sinuation at the posteriorend of the ventral margin depicted in Sowerby's figure. Hiswords " concentrically ridged behind the angle " are scarcely applicable,for in the first place there is only the feeblest indication of anangle and the sculpture behind it consists of mere concentric striation.The hinge-characters show this species to belong to the genustSynclosmya, and Tellina simplex of the same author (Conch. Icon,sp. 240) requires a similar location. The hinge of the present speciesconsists of two cardinal teeth in the right valve, the posterior largerh2