MOLLUSCA. 837 



Remarks. — This species is known from New Jersey by a single 

 fragmentary individual preserved in the collection of the Phila- 

 delphia Academy of Science. The sutures are very complicated 

 and consist of a large ventral lobe which is deeply divided by a 

 comparatively narrow ventral saddle trifid on top and reaching 

 nearly tO' the mid-height of the lobe, and three lateral lobes ; all 

 the lobes are much complicated by deep and sharp divisions, the 

 divisions of the saddles being more rounded. 



Formation and locality. — Unknown, New Jersey (Whitfield). 



Geographic distribution. — New Jersey, Texas. 



Family PRIONOTROPIDAE. 



Genus Mortoniceras Meek. 



Mortoniceras delawarensis (Morton). 



Plate cm., Fig. I ; Plate CIV., Figs. 1-5. 



1830. Ammonites Delawarensis Mort., Am Jour. Sci., ist sen, 



vol. 18, pi. 2, fig. 4. 

 1830. Ammonites Vanuxemi Mort., Am. Jour. Sci., ist ser., 



vol. 18., pi. 3, figs. 3-4. 

 1834. Ammonites Delawarensis Mort., Synop. Org. Rem. Cret. 



Gr. U. S., p. 37, pl- 2, fig. 5- 

 1834. Am^nonites Vanuxemi Mort., Synop. Org. Rem. Cret. 



Gr. U. S., p. 38, pl. 2, figs. 3-4. 

 1861. Ammonites Delawarensis Gabb, Synop. Moll. Cret. 



Form., p. 65 (9). 

 1864. Ammonites delawarensis Meek, Check List Inv. Foss. N. 



A., Cret. and Jur., p. 24. 

 1868. Ammonites delawarensis Con., Cook's Geol. N. J., p. 730. 

 1892. Ammonites Delawarensis Whitf., Pal. N. J., vol. 2 



(Monog. U. S. G. Ss vol. 18), p. 252, pl. 42, figs. 6-9, 



pl. 43, figs. 1-2. 

 1892. Ammonites Vanuxemi Whitf., Pal. N. J., vol. 2 (Monog. 



U. S. G. S., vol. 18), p. 253, pl. 42, figs. 1-5- 

 1905. Ammonites delawarensis Johns., Proc. Acad. Nat. Sci. 



Phil., 1905, p. 27. 



