64 THE NAUTILUS. 



CONTRIBUTIONS TOWARDS THE KNOWLEDGE OF THE MOLLUSCA OF 



MADAGASCAR. 



BY C. F. ANCEY. 



Helicarion (?) Dautzenbergianum Anc. 



Testa imperforata, convexo-depressa, angulata, tenuis, pellucitia, 

 nitens, corneo-virens, supra angulum medianum fascia rubrofusca sat 

 angusta circumdata, indistincte et obsolete lineis radiantibus sub- 

 plicosa. Spira depresso-conoidea, subobtusa, convexa. Anfractus 

 A^ celeriter crescentes, subconvexi, sutura distincta sed baud {)ro- 

 funda; ultimus magnus, dilatatus, utrinque convexus, medio angu- 

 latus, basi subtumidus. Apertura ampla, distincte obliqua, extus 

 angulata, lunato-oblonga, leviter supra convexo-producta, basi regu- 

 lai-iter usque ad columellam arcuata, marginibus remolis. 



Diam. maj. 18, min. 15^, alt. 9^, alt. apert. (oblique) 9 mill. 



Hab.: " Montague d' Ambre," N. Madagascar. 



A very remarkable species on account of the keel and its very 

 peculiar shape and coloration. It may, perhaps, be referable to 

 Euplecta or Hemiplecta. 



Euphcta oxyacme Anc. 



Testa fragilliraa, subimperforata, conico-trochiformis, parum 

 nitens, opacula, corneo-lutescens, concolor, sub valida lente lineis 

 confertissimis incrementi notata et striis argutis permultis spiraiibus 

 decussata, subtus paulo nitidior. Spira elevata, perfecte conica, 

 rectilinearis, acuta. Anfractus G regulariter crescentes, priores con- 

 vexiusculi, inferi applanati, sutura lineari, appressa ; ultimus acute 

 et compres^e in medio carinatus, infra convexus, supra carinam 

 planodeclivis, antice baud deflexus. Apertura lunata, extus angu- 

 lata, subobliqua, marginibus distantibus, supero recto-declivi, basali 

 regulariter arcuato, columellari leviter supra perforationem parvulam 

 expansiusculo, earn fere prorsus occultante. 



Diam. maj. 13:|, min. 11|, alt. apert. oblique 5|, alt. 9^ mill. 



Hab.: Antankaratra Country (Humblol). 



Of the same shape and size as Rotula argentea, Reeve, but of 

 thinner texture and different color. It may belong to the same 

 genus, but is perhaps related to Evplecia {'?) feneriffensis, Angas. 

 The generic reference, therefore, is doubtful. 



