INSLILARIM MADIÍREXSIUM lfl7 



Siplioiip brcri. Palliali liiiea simplici 



Intooro-pallialia 



Fniii. CYCLADIDAE 



Testa suborbiciilaris: ligameiíliim exlei'iiuiii; epiderniis densa, córnea: um- 

 bones in adultis erosi; articulus eentralibus dontibus, lateralibus aliis instmclus; 

 pallialis linea suliinflexa. — Animal teslam lieniielice claudens, pallio antice aperto, 

 ad marjíines plano, sipbonihus 1-á [)lus minusve conjunctis, ad orificia planis, 

 branchiis amplis, inaeqiialibus, poslice junclis, palpis lanceolatis, pede lalo, lin- 

 guiformi. In regionum subborealium rivulis de''il. 



o 



Geií. Pisidium, Pfeiífer 



Testa inaeqnilatera, antice ion.íior. — Animal párvulo tubo, excurrente, aper- 

 tura ad aqiiae ingressum pedisque egressuni ada[itata, muiiitum.— In rivuloriiin 

 fluentibus aquis Americae, Algeriae, septentrionalis Europae et mediae, Indiae 

 habitat. 



Pisliiiiim? Walsoni, Paiva 

 (Tab. 2, llg. 10) 



Testa ovato-subangularis, valde compressa, tenuis, nilidula, striis exilibus, 

 concenlricis, irregulariter insculpia, lutescenti-albida v. cinerascens, intus albo- 

 fuscescens, saepe aureo-rubello nilens; latus anticiim subquadrangulare, fere trun- 

 catum, poslicum rotundatum, gradatim declive, magis produetum; utiumijue di- 

 stincte compressum; margo inferus rotundatiis; extrema obtusa, nec prominentia; 

 ligamentum beve, qiiasi inconspicuum: axis brevis, validissimus. — Animal tar- 

 dum, testam semirotatorio mota propellens, corpore albido, luteo v. rubro-lin- 

 clo, tubo bievi, subconico v. cylindrico, ad oiilicium parvulum olilique truncalo, 

 valde dilatabili, p£de pellucido, stricto, incurvo, longo, testa longiore, v. testam 

 aequaiite, pallio pulposo, albo-marginalo. 



Long. 4, larg. 3^4 niill. 



Pisidium Watsoni, Paiv. Journ. de Conch. Crosse. oct. 1866 (fig. bona) 



Habitat freqnens in Maderae aqnis slagnanlibus, ad aquaeductum Levada 

 do Bom Siicccsso prope Funchal baud rara. 



Obs. A P.-fontinali Drap., cui certe alFine, testa ovali, nec triangulari, de- 

 pressiore, pallidiore, nolistjue aliis dillert. 



