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Show 598 MR. G. B. SOWERBY ON NEW SPECIES OF SHELLS. [Nov. 3, its favour is that the combination of anatomical characters is exactly the same in all its genera, which have a very scattered distribution. It will be noticed that no Parrots with normal carotids occur in the N e w World; and, as far as I know, none but members of that group have red beaks. P.S. (December 8th, 1874).-On the 25th of last month, from the death of one of the specimens of Stringops habroptilus, recently purchased by the Society, I have had an opportunity of dissecting a third individual of the species. In it the ambiens muscle is complete, of fair size, at the same time that it crosses the knee as in Psittacus. This makes me feel more convinced that the arrangement indicated by the dotted portions of the diagram plates accompanying this communication is the correct one, and that the main stem has given rise to three instead of two branches-the Stringopinae being the nearest representatives of the ancestral form, some of its members (Geopsittacus, Melopsittacus, Euphema, and Cganorhamphus) having quite recently lost, whilst Stringops itself is just now on the point of losing the ambiens muscle. It is, however, quite possible, if external resemblances and geographical distribution are left out of consideration, that Stringops must stand as the sole representative of the Stringopinae, thus conforming with generally received ideas; and that Geopsittacus, together with Melopsittacus, Euphema, and Cyanorhamphus, must be placed with Agapornis as part of the family Agapornithinae, in which the formula is 2 , - , - , + . The close external resemblance between Stringops and Geopsittacus nevertheless makes m e indisposed to adopt this view. 7. Descriptions of five new Species of Shells. By G. B. SOWERBY, Jun. [Eeceived September 15, 1874.] (Plate LXXII.) 1. T R I T O N (EPIDROMTJS) C O M P T U S , sp. nov. (Plate LXXII. figs. 5, 5 a.) T. testa oblongo-turrita, rufo-fusca, castaneo maculata, undique creberrime decussate lirata, liris eximie granulosis, interstitiis transversim striatis; anfractibus rotundatis, maculis angustis oblongis transversim balteatis; varicibus paucis, rotundatis, castaneo grandimaculatis; apertura subexpansa, labia externo refiexo, lavi, ad marginem lineis castaneis minutis notatis; lamina columellari lavi, pellucida, polita; canali brevissima recurvo: long. 54, lat. 20; apert. long. 20, lat. 10 mill. Shell of the usual general form of an Epidromus (Klein) as separated from the genus Triton (Lamarck), reddish-brown colour, blotched and spotted with dark chestnut-brown, closely and exquisitely cancellated and granulated; whorls rounded, belted with narrow oblong spots; varices few, rounded, with large chestnut blotches; aperture rather expanded; outer lip refiexed, smooth, with small |