250 PALEONTOLOGY OP NEW JERSEY. 



scription of their characters, though the anterior scar appears to have been 

 tolerably large and well marked. The surface of the shell has been marked 

 by rather strong concentric wrinkles for one of this usually smooth type. 



Mr. Lea mentions in his original description of this species that the 

 cardinal teeth are "oblique and compressed, lateral teeth long, large, lamel- 

 lar, and very slightly curved." 



TJnio praeauodontoides, u. sp. 

 Plate XXXI, Fig. 2. 



Shell cylindrical, a little less than three times as long as high, and 

 about four-fifths as thick through the closed valves as the heiglit from the 

 hinge-line to the base of the shell. Hinge-line rather straight and long, 

 beaks small and inconspicuous, situated a little less than one-third of the 

 entire lengtli of the shell from the anterior end. Anterior end narrowly 

 rounded; posterior end long and nasute; the point of greatest lengtli 

 almost on a line of the center of the valve. Body of the shell marked just 

 forward of the middle by a broad shallow mesial depression passing from 

 tlie beaks to the base of tlie shell Anterior teeth moderately strong; lat- 

 eral tooth long and slender, but strongest near the posterior end. Muscular 

 scars faintly marked. 



Tlie shell is remarkably similar to the narrowly cylindrical forms of 

 U. anodontoides Lea. It is perhaps not quite so high from base to hinge, 

 but in other respects is exceedingly like it. The posterior end is also per- 

 haps slightly narrower, and in this respect resembles in form U. nasutus; 

 but the valves are much more ventricose, have not that angularity of the 

 posterior umbonal slope, and differ essentially in the shallow sulcus crossing 

 the valves. The specimen used retains both valves, but spread widely open. 

 It is the property of Prof. Henry Carville Lewis, of Philadelphia, who 

 kindly loaned it to me with other specimens of the various species here 

 described. 



TTnio rectoides, n. sp. 

 Plate XXXII, Figs. 1 and 2. 



Shell very elongate with subparallel basal and cardinal margins, the 

 former very slightly sinuate near the middle of the length; anterior ex- 



