— 151 —. 
3. Gen, Unio Phil. 
98. Unio pietorum L. _ 
99. — tumidus Nils, 
100. — batavus Lam. 
Il. Fam. Cyeladidae. 
4. Gen. Sphaerium Scop. 
101. Sphaerium rivicolum Leach. 
102. — corneum L. 
5. Gen. Calyculina Cless. 
103. Calyeulina lacustris Müll. (= calyculata Drap.) 
6. Gen. Pisidium C. Pf. 
104 Pisidium amniecum Müll. (= obliquum Pf.) 
105. — fossarinum (less. (= fontinale Pf.) 
106. — obtusale C. Pf. 
107. — nitidum Jen. (von Clessin unter Pisidien aus 
Jensel aufgefunden). 
III. Fam. Dreissenidae. 
7. Gen. Dreissena Ben. 
108. Dreissena polymorpha Pall. 
Diagnosen neuer Arten. 
Von 
W. Kobelt. 
Helix (Xeroleuca) Libyca Ponsondy mss. 
Testa sat anguste sed pervie umbilicata, orbiculato 
depressa, apice tantum prominulo, irregulariter stri- 
atula et inter strias erispato-rugulosa, sutura impressa, 
inter anfractus superos distincte erenulata, versus aper- 
turam lineari ; cretacea, sordide albida. Anfractus 5, 
regulariter crescentes, primi 1!/, apicem prominulum 
laevem lacteum formantes, sequentes supra plani, 
