1894.] 



MICROSCOPICAL JOURNAL. 



113 



VII. Cephalis simple. 



SECTION A. CEPHALIS ONLY. 



27.— Family : TRIPOCALPIDA. Three radial apo- 

 physes, 1. e., ribs, wings, spines, or feet. 



Three feet. Horn. Three lateral ribs. Tripocalpis. 



Three feet. Horn. No lateral ribs. Tripilidimn. 



28.-Family: PH^NOCALPIDA. Numerous radial 

 apophyses. 



BASAL MOUTH OPEX. 



Radial ribs. Oinclojjyrai/iis. 



No radial ribs. Horn. Halicalyptra. 



No radial ribs. No horn. Carpocanistruin. 



BASAL MOUTH CLOSED. 



Free columella in axis of shell cavity. Phce7iocalpis. 



29.— Family : CYRTOCALPIDA. No radial apophy- 

 ses. 



BASAL MOUTH OPEN. 



Shell conical, dilated. Cornutella. 



Shell ovate, constricted. Horn. Archicorys. 



Shell ovate, constricted. No horn. Cyrtocalpis. 



BASAL MOUTH CLOSED. 



Horn. Halicapsa. 



