87 



Synopsis moliusconim marinorum 

 Indiarum occideiitalium. 



auctore O. A. L. Mörch. 



(Contin.) 



Farn. Ceritliiacea. 



Sub-Fam. i. Potamidinae Ad. 



Operculum orbiculare mullispirale. 



Cerilhidea Sws. 



* Labro tenui reflexo, 



210. Cerithidea scalariformis Say. 



„Sh. turi-ited, gradualh^ tapering to the apex, which 



is acute, whorls rounded, crossed by numeroiis elevated, 



regulär lines, Avhicli on tlie body wliorl, are terminated 



ncar the base by 5 or 6 more or less profound revolving 



gruoves, suture pretty decply impressed, with generally 



one of the grooves above it, so as to appear double: 



culour pale, with several revolving reddish brown lines; 



aperture rounded : labrtim tliickened, somewhat recurved ; 



a sliglit but obvious sinus at base, and another very 



sligth, more obtuse one new the junction with the pre- 



ceeding wliorl, mnbilicus none." Say. 



Lgth. 7io iii'^'hj operculum small; Eyes a little 

 above the base of the tentacles (Say.) 



Pireua scalariformis Say. Journ. xVc. of N. S. Phil. 

 1825. p. 128. 



Pirena scalariformis Dekay New-York p. 128. 

 Cerithium scalariforme Sow. Thes. p. 88Ü. Nr. 174. 



£ 290? C ■ 'Vi-iA-^cU^t^^- "'■-■, "■■-^•■'^ H'T i.-:V, 



■ / 



Hab. in the freshwater lakes in the Florida Keys 

 abundant (Tit. Peale.) 



211. Cerithidea tenuis Pfr. 

 T. turrita, tenui, longitudinaliter plicata, unicolore 

 albida, vel violaceo-fusca, fasciata; anfr. 11 convexie. 



