1863.] COLLECTED IN MADAGASCAR BY MR. CALDWELL. 6f 



whorl it approaches the Australian group Ameria of H. Adams, yet, 

 from its singular Urate character, may probably itself prove the type 

 of a peculiar subgenus. 



4. LimnjEa (Drap.) hovarum, nov. spec. 



Testa imperforata, ovato-globosa, tennissima, pellucida, nitidis' 

 sima, longitudinaliter siibtilissime striata; sutura simplex; 

 spira depressa, apice acuta; anfract. 3|, convexi, ultimus ^, 

 longitudinis subrequans ; apertura obliqua, ovato-globosa ; pe- 

 ristomium rectum, simplex, margine columellari rejlexo, margi- 

 nibus callo tenuijunctis. 



Shell imperforate, ovately globose, very thin, transparent, very 

 glossy, very slightly striated lengthways ; the suture plain ; the spire 

 depressed, with a sharp apex ; 3g whorls, convex, the last occupying 

 four-fifths of the length of the shell ; the aperture oblique, ovately 

 globose ; the peristome straight and simple ; the columellar fold re- 

 flected, its edges joined by a thin skin. 



Long. .Tg lin. ; lat. 3| ; apert. long. 4| ; lat. 3. 



Hab. Two days west of Antananarivo, Madagascar. 



5. Planorbis (subgen. Nautilina, Stein) caldwelli, n. sp. 



Testa discoidea, albido-cornea, nee striata, nitida, hispidula, supra 

 forte convexa, umbilicata, subtus plana, paulo foveolata ; an- 

 fract. 4-5, supra convexi, ultimus acute carinatus ; apertura 

 obliqua, sublunaris ; peristomium rectum. 

 Shell disc-shaped, horny white, not striated, shining, rather rough, 

 strongly convex above, umbilicated, flat below, and slightly pitted ; 

 four to five whorls, convex above, the last sharply keeled ; the aper- 

 ture oblique and crescent-shaped ; the peristome straight. 

 Diam. maj. 2|- lin. ; min. 2 ; alt. apert. | Hn. 

 Hab. Two days west of Antananarivo, Madagascar. 

 The nearest congener of this species is an unnamed species from 

 Natal, in Mus. Cuming. 



6. Cyclas {Sphcerium, Scop.) madagascariensis, nov. spec. 

 Testa suborbicidaris, subincequilateralis, ventricosa, tumida, ad 



margin, paulo compressa, irregulariter concentrice striata, 

 rubigine radiata, olivaceofusca, zonis pallidioribis intersper^ 

 sis, margine dorsali utrinque compresso et expanso ; natibus 

 acutis, integris, proximis, natreo resplendentibus, valde pro- 

 minentibus ; ligamento subinfosso. 



Shell suborbicular, slightly inequilateral, ventricose, tumid, slightly 

 compressed towards the edges ; irregularly striated concentrically, 

 and faintly radiated with rust-colour ; olive-brown, interspersed with 

 paler zones ; the dorsal margin compressed and expanded on both 

 sides ; the umbones sharp, perfect, close together, with a nalreous 

 lustre, very prominent ; the ligaments buried. 



Long. 4^ lin. ; lat. 3| ; alt. 2^. 



Hab. Two days west of Antananarivo, Madagascar. 



I 



