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



Cytherea multistriaia, Sowcrby, Cytherea diemenensis, Ilauley, aud young specimeus 

 of Cytherea viuUiradiata, Sowerby. Cytherea disrupta is a more solid shell than 

 Cytherea midtistriata, uot (|uite so acute posteriorly, with the valves peculiarly thickened 

 at the margins, the dorsal area conspicuously blotched, the luuule for the most part white 

 aud concave in the middle, the dorsal line on this side being excavated in consequence. 

 On the other hand, in Cytherea midtistriata, the lunule is coloured, not sunken in the 

 middle, the dorsal outline straight, the posterior area generally more faintly blotched, 

 and the edge of the valves is acute. 



The latter species is also differently striated, the tone of its colour not quite similar, 

 the hinge even slighter, and tlie beaks not, as a rule, rosy at the tips. 



Cytherea diemenensis, 11avl\qj^= Cytherea innocens, Bowevhy = Cytherea multi- 

 striata, Romer'' and Reeve ^ {non 8owevhy) "^ = Cytherea planatella, Lamarck,* is not so 

 oval as the species above described, has the anterior dorsal margin straight and much 

 more descending, and more regular markings, the interior displaying only a single 

 purplish ray directed posteriorly from the umbones. 



, Cytherea (Callista) roseotincta, n. sp. (PL I. figs. 6-6/>). 



Testa transversim ovalis, valde incequilateralis, nitida, striis coucentricis tenuissimis, 

 antice paulo distinctioribus, sculpta, albida, roseo (marginem versus radiatim) irregulariter 

 tincta, area et lunula maculis paucis parvis notatis. Margo dorsi posticus elongatus, 

 leviter arcuatus, paulo obliquus, anticus declivior, subrectilinearis. Ventris margo late 

 regulariterque arcuatus. Umbones parum elevati, incurvati, apicibus rosaceis, in 

 circiter ^ longitudinis positis. Lunula elongato-cordata, leviter depressa, medio 

 promiuens, linea elevata circumdata. Cardo mediocriter fortis, dentibus erectis 

 approximatis. Pagina interna alba, umbones versus pallido-roseo sub-biradiatim suftusa. 

 Cicatrix autica parva, acute ovalis, postica major, rotundata. Sinus pallii profundus, 

 latus, ad apicem oblique truncatus. 



This species is only moderately convex, transversely oval, a little narrower in front 

 than behind, very inequilateral, of a whitish colour copiously mottled and stained with 

 light fleshy pink, which towards the margin is of a darker tint and disposed in rays. 

 The dorsal area has a few cross-bars of the same colour, and the lunule is also lineated 

 with it. The valves are glossy and very finely concentrically striated, except at the 

 anterior side, where the stria3 are rather deeper and coarser. The hinder dorsal margin 

 is elongate, a little obliquely and slightly curved, the anterior being much shorter, more 

 descending, and almost straight. The lower outline is gently arcuate, aud ascends a 



' Proc Zo:>l. Soc. Land., 184-4, p. Uli. ^ Monogr. Venus, subgenus Cytherea, p. 72, pL xxi. tig. 1. 



^ Conch. Icon., fig. 6e, ^ Anim. sans Vert., ed. 2, vol. vi. p. 30."). 



