PROCEEDINGS OF THE ACADEMY OF 



[Feb., 



The third rostrum (text fig. 1), which is that 

 mentioned by Leidy in 1869 under Priscodeliphinv.s 

 (or Tretosphys) grandcevus,'' and also figured by 

 Mr. Case,^ has, as already mentioned, no close 

 relationship with the other two. It may for the 

 present be considered as representing a species of 

 Priscodelphimis, although, as explained in a previ- 

 ous paper, ^ the reasons for referring it to that genus 

 are not satisf actor}'. 



The principal peculiarities of the rostrum are 

 that the premaxillse are much depressed, but not 

 narrowed, anteriorly, that the anterior alveoli are 

 larger than the posterior ones and directed for- 

 ward, and that the external free border of the 

 maxillae is rounded (see text figs. 2 and 3). 



Fig. 2. — Transverse section of the s.-ime at the posterior 

 end. (Nat. size.) 



Fig. 3. — ^Transverse section of the same at the anterior end. 

 (Nat. size.) In figs. 2 and 3 the maxillse are indicated 

 by horizontal lines and the premaxillce bj- oblique lines 



Fig. 1. — Rostrum of 

 Pris codelphinus 

 sp.? from the Mio- 

 cene of Shiloh , N . J . 

 Superior surface. 

 Q nat. size.) 



The three teeth which were provisionally 

 referred to Rhabdosteus by Cope are preserved in 

 the Academy of Natural Sciences of Philadelphia, 

 and were examined by me in 1907. Very good 

 figures of the largest one were published by Cope 



' Journ. Acad. Nat. Sci. Phila., Ser. 2, Vol. 7, 1869, p. 434. 

 8 Rep. Maryland Geol. Surv., Miocene, PI. 15, fig. 1. 

 ^ Smithsonian Misc. Colls., Quarterlv Issue, 50, Pt. 4, No. 

 1782, p. 451, January 27, 1908. 



