' Descriptions of Species. 35 



liclcctico Pictet and Renevier. Muter, pour la paleont. 

 Suis.sc du ter. aption, 1854. 



' Casslopc helvetica H. Coquancl. Monogr. paleont. de Pet. aptien 

 de PEspagne, 1866. 



Ccrlt/tiuni liijani Verneuil. Bull, de la Soc. Geol. de France, 

 2e liv. Tome x. 1853. 



('< ritJiiii.ni la.cani Verneuil. Memoria geognostica de-Castellon 

 par Vilanora, 1859, plate iii, Fig. 7. 



Cassiope verneuilli H. Coquancl. Monogr. paleont. de Pet. apt. 

 de PEspagne, I860. 



Mnrex strombiformis Schlotheim. 1820, Petrefact., p. 144. 



Murtcitcs strombiformis Schlotheim. Monographic der Nord- 

 deutschen Wealdenbildung, Dunker, 1846, p. 50, pi. x, fig. 18a, ft. 



This form is indistinguishable from the figures of V. lujaniund 

 V. helvetica of De Verneuil and De Loriere, but without compari- 

 son of type specimens their identity cannot be positively as- 

 serted. V. lifjani is described as follows : 



"Shell elongated, with thick test; spire regular, straight, or 

 sometimes a little pupoid ; ten or twelve turns of the spire. 

 Each turn of the spire is marked by numerous sinuous cross- 

 stria), strongly bent inward upon the first anterior quarter of 

 each spiral. The sutures are generally well defined." The 

 whorls are also usually marked by two longitudinal elevated 

 bands, one near each border, which in the apical whorls and 

 adult specimens appear as plain elevated bands, or may be in 

 the lower two-thirds of the shell nodular. They continue upon 

 the buccal face or base of the shell as bands. kt The lip always 

 presents at the posterior or upper end a pronounced gutter. The 

 outer lip has a deep, broad indentation corresponding with the 

 termination of the basal suture line beneath the last carina or 

 row of tubercules. The inner margin of the labial opening is 

 thickly encrusted." De Verneuil. 



This is one of the most abundant, variable, and characteristic 

 forms of the Trinity Division, occurring in the lowest molluscan 

 horizons of the Glen Rose beds throughout its extent from An- 

 toine, Arkansas, to the Colorado river in Texas. It was first 

 figured from America by the writer in his report upon the Cre- 

 taceous beds of Arkansas under the name Plcurocera strombi- 

 fonnis Schloth., after Zittel. Although a very abundant form, the 

 oral aperture was only recently discovered, it having hitherto 

 been broken in the delicate structure of the specimens, and the 

 generic position thereby made uncertain, as is attested by the 

 widely different genera to which it has been referred in Europe, 



