()2 MOLLUSCA TERRESTRIA ET FLUVIATILIA 



Obs. Testa Planorbis formam refert, qiiamqiiam vere helicea. 

 Species sic dicla oh spiiam valdo dcpressaiii. paiiperciilam, quasi niilkim. 

 — A coiigeneiil)us certe distiiu-lissima. 

 Pi'imiis clariss. Rev/ Loweus invenit. 



(e) TESTA MAMILLATA, MAIMILLIS PLIS :\f!NrS CROSSIS, 

 V. TUBEHCULATA 



56. Helix tliiarella, ^V.,■hlJ. et Berthelol 



Testa unibilicala, trocliiformis, albo-cinerascens, talcarea; spira coiiica, 

 apice obtusa; siiliira impressa: umliilicus paliiliis, peivius, iiitiis aeqiie ac in 

 basi sculptus; anlVacliis G-7 medio liiiea elata, qiiasi cariiiata cincli, supra re- 

 gulariter transverse strigati, infra undato-granulali, ultimus ad basiii biieis cori- 

 centricis, inlerruplis sulcatus, anlice angulalim deflexus; apertura obliqua, obloii- 

 go-rotundata: perislonia tenue, continuum, solutum, undique expansiuscuUun, 

 aiitido-cariieum. — Animal valde liniidum, coipore pailide ocliraceo s. albido, 

 (juandoquidem aiiiido-iiitesrerite v. nigrescente, tuljcrculis tenuissimis, alliidis 

 asperso, fronte sublutescente, sufierioribus tentacuiis longis, cylinfb^ae^eis. fusco- 

 niaculatis, basi remotis, crassiusculis, ai)ice giaciiiitus, rolundalo subbulbosis, 

 inferioribus brevissimis, albis, triangularibus, fere inconspicuis, pedc lutescente, 

 peliucido, postice acutiusculo, antice obtuso, lateraiiter plúmbeo, pallio fusco- 

 colVaeaceo, orifício rcspiialoiio subnilido, spbiiiclere integro, sublubuloso cir- 

 cumdato. 



Diam. maj. G''-2, min. o, alt. 5V2 miii. 



Helix tbiaiclla. Web. el iierlh. Syn. 

 » » Pfeif. Mon. helir. 



» » Recv. ('ondi. (fig. óptima) 



» » Alb. Mal. Mad. (fig. óptima) 



» » Low. Cal. moll. Mail. 



Habitat copiose in Madeiae insulae collibus maritimis iiiler S.'" Anna et 5. 

 Jorge vifos, [)raecipui' ad rupcni praeiiiplam lUnhit das Cnhras sub foliis emor- 

 luis, ad Ilijjiprivornm caules, Sewpervivorum idliis adharrens. in jiromontoriis 

 S. Lourenço, Gnr/ijiio, rarior ad frulicum ramos: fossilis copiosissime prope Ca- 

 niçal, raiissima ad Zimbral dÁrèa in Portosancto insula. 



Obs. Cúm juvenis, H.-coroiiatam Lowe (jiiodammodo referi. 



Obs. Clariss. S. Bcrtlielotus in insula Tenerilía specimina fossilia mccum amice 

 communicavit, maderensibus omnino siniilia, quae illic ccrlissime a Madera in- 



