146 COLORADO FORMATION AND ITS INVERTEBRATE FAUNA, [buil.106. 



border of this process is slightly convex and continuous with the outer 

 border of the body of the wing 5 the extero-anterior border of the wing 

 abruptly rounded, from which to the very short beak the border is 

 sinuous, almost sigmoid ; posterior border. of the wing deeply concave, 

 its proximal half being slightly reflexed outward, as if for the passage 

 of soft parts corresponding to those that in allied genera occupy a pos- 

 terior canal, as the curved sinus adjacent to the columella doubtless 

 gave passage to soft parts corresponding to those that in Anchura 

 proper occupied the anterior canal or channel of the beak ; inner lip pro- 

 vided with a distinct and moderately broad callus, which, in some cases 

 at least, extends beyond the distal end of the aperture across the next 

 volution, as seen by dorsal aspect of the shell; columella very slightly 

 produced in front, and its apex flexed a little toward the dextral side of 

 the shell. Volutions of the spire marked by many longitudinally ob- 

 lique folds, which extend to the suture on the proximal side of the 

 volutions, but not much beyond the middle on the distal side, and do 

 not. appear at all on either the body- volution or wing. The whole sur- 

 face marked by fine revolving strise, which are more distinct upon the 

 last volution than elsewhere; last volution and wing also marked by a 

 moderately strong carina, which terminates at the point of the falci- 

 form process. 



u Length, 16 mm ; breadth across the body- volution, including the 

 wing, 12 mm . 



" This species agrees well with the subgeneric diagnosis of Meek for 

 Drepanocheilus, and in many respects it resembles A. (_D.) americana 

 Evans and Shumard sp., but it differs from that shell in its large ante- 

 rior sinus, the deep sinuosity of the anterior border of the wing, and 

 the reflexion of a portion of the posterior margin of the wing." 



Locality and position. — Upper Kanab valley, Utah, from same horizon 

 as the preceding species. 



STROMBID^E. 



Genus LISPODESTHES White. 



This name was proposed 1 to include two species, Lispodesthes nuptialis 

 and L. lingulifera, now regarded as one. 



It was characterized as follows : 



u Shell fusiform; anterior canal straight or slightly curved, and more 

 or less produced; posterior canal extending nearly or quite the whole 

 length of the spire, from near the apex of which it may be a little 

 deflected; aperture winged; wing rather large, bearing two processes; 

 the posterior process spine-like or falciform ; the anterior process either 

 in the form of a lobe or tongue-shaped ; inner lip and spire covered 

 with callus." 



To this description it should be added that in the adult the wing is 



» U. S. Geog. and Geol. Sur. West 100th Merid., vol. IV, p. 191 



