NEW PALEOCENE Mi^iMMALS SIMPSOIT 227 



Genus PARECTYPODUS Jepsen 



* 7PARECTYPODUS JEPSENI,' new species 



Tyjye.—U.S.^M. no. 9769, left lower jaw with P4-M1. Col- 

 lected by A. C. Silberling. 



Horizon and locality. — Gidley Quarry, Fort Union, Middle Pale- 

 ocene horizon, Crazy Mountain Field, Mont. 



Diagnosis. — (Type specimen unique.) P3 absent and no notch in 

 base of P4. Distantly suggestive of Paredypodus simpsoni, but very 

 distinct, with fewer serrations on P4, absolutely and relatively longer 

 Ml, and markedly different cusp formula of Mi. Length P4 4.3 mm. 

 Length Mi 3.1 mm. Ratio length P4 : length Mi 1.4. Ratio length 

 Ml -.width Ml 2.2. Serrations P4 11. Cusps Mi 7:6. P4 long 

 and low. 



Order INSECTIVORA 



Family ?DELTATHERIDIIDAE 



Subfamily Didelphodontinae 



GELASTOPS.io new genus 



Type. — Gelastops parens, new species. 



Distribution. — Middle Paleocene, Fort Union, Mont. 



Diagnosis. — Resembling Didelphodus in the Ivnown parts but canine 

 more erect, premolars more crowded, trigonid of Mi longer relative to 

 talonid, trigonids of M2.3 sliorter and more elevated, M2 and partic- 

 ularly M3 smaller relative to Mi. M^ (referred) extremely short and 

 wide, paracone and metaoone slightly more external than in Didel- 

 phodus, metaconule vestigial, no trace of hypocone. 



GELASTOPS PARCUS," new species 



Ti/jpg.— U.S.N.M. no. 6148, right lower jaw with canine, Mi, M3, 

 and alveoli. Collected by A. C. Silberling. 



Horizon and locality. — Referred specimens from Gidley Quarry, 

 type probably from same level. Fort Union, Middle Paleocene horizon, 

 Crazy Mountain Field, Mont. 



Diagnosis. — Sole known species of genus as defined above. Mi 

 (type) length 3.5 mm, width 2.3 mm. M2 (referred specimen) length 

 2.5 mm, width 2 mm. M3 (type and one referred specimen) length 

 2.7-2.9 mm, width 1.8-1.9 mm. M^ (referred specimen) length 2.7 

 mm, width 5 mm. 



' Niuned for Dr. Q. L. Jepsen for his work on the Paleocene of Wyoming. 

 1" rtXaffToi, peculiar+o)!^, aspect. 



" ParcuK, thrifty, small. From its scanty remains and its small size. Gidley noted this as new but left 

 no designation or diagnosis. 



