4 KOBELT : ON THE LAND SHELLS OF GIBRALTAR. 



pelhicida, nttens, cornea, spira vix elevata, sutura dis- 

 tincta; aufractus ^ convexiusculi, ultimus depressus, basi 

 siibplanatus, apertura lunato-ovata, peristo77iati siviplici 

 margine basali parum araiato. 



Diajfi. viaj. lo ; inin. 8. Alt. vix. 4. mill. 



Shell thin, almost cylindrical, umbilic passing right 

 to the apex, but only showing very little of the second 

 whorl, depressed, striations on the top distinctly visible 

 by the lens, while underneath the shell is smooth, 

 tolerably transparent, glossy and horn-colored. The 

 shell is only slightly elevated with a distinct and deep 

 suture. The five whorls are somewhat arched and 

 increase regularly, the last one only a little expanded, 

 depressed, flattened at the base and almost obtusely 

 angular. The aperture is oval in shape, pretty much 

 rounded off, the peristome is simple and thin, the basal 

 margin almost horizontal. This species resembles the 

 Sardinian Hyali?ia opaca Shuttl. (Icon., fig. 1619), but 

 it is smaller, the last whorl not so distinctly angular 

 and the striation fainter. 



4. Hyalina Dauthezi n. sp. 



Testa mediocriter 2imbilicata , depressa, superne plana 

 vel leviter concava, ifitra convexa, fere planorbiformis, 

 distincte striata, supra olivaceo-cornea, infra albida, sat 

 solida; spira parva, siibinwiersa, apice minimo. Atifrac- 

 tiis J", sutura impressa distincte marginata discreti, superi 

 lente inflatus basi cofivexus ; apertura rotundalo-ovata 

 fere verticales valde lunata, peristomati si^tipHci, regula- 

 riter arcuato. 



Diam. maj. 10; min. 8. Alt. 4. mill. Apert. 

 5 mill. lat. 4 mill. alta. 



Only two specimens of this highly interesting 

 planorbis-shaped form lie before me, which are perhaps 

 not fully developed, according to my friend Boettger, 



J.C, iv., January, 1883 



