46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69] 



continental form is not, however, entirely clear ; specimens examined, 

 as remarked by Allen (/, c), seem " not apparently distinguishable " 

 from typical D. m. etensis. On the other hand they are not very 

 unlike typical examples of the apparently larger subspecies D. m. 

 richmondi of Nicaragua, and may be somewhat intermediate in gen- 

 eral characters. As in other forms, of the general group two color 

 phases are shown. The usual color of the pelage is blackest at the 

 tips, but in about one-third of the individuals examined, long whitish 

 hairs are predominant among the black ones. This dichromatism 

 has led to the belief in many localities that two distinct species exist 

 side by side. 



While this form may be said to be abundant it occurs in smaller 

 numbers at most localities than M etachiru^ opossum fuscogriseus. 

 It favors the vicinity of streams or other water, along the muddy 

 borders of which numerous palmate tracks may be seen. While 

 using a hunting lamp in quest of more important game a number 

 were shot at night along the banks of streams. The species is easily 

 taken in steel traps baited with meat or fruit, especially bananas, of 

 which they are very fond. When caught the ground and vegetation 

 within reach are thoroughly torn up by the animal in frantic struggles 

 to free itself, but on hearing some one approach it instantly becomes 

 quiescent and " possums " in the characteristic manner. The body 

 becomes motionless, in a half-crouched position, the head drops 

 slightly, and unless the eyeballs are touched the eyes have a fixecf 

 stare. Given a slight push the opossum tumbles over on its side and 

 lies with rigid limbs and muscles as though dead. In this condition 

 it may be handled freely, making no attempt to bite or even to stir 

 and about the only sign of life is its regular breathing. Removed 

 from the trap it may be left lying motionless and apparently dead 

 upon the ground. But it is sure to be gone if the trapper retires 

 and returns to search for it a few minutes later. 



A female trapped at Gatun had five hairless and sightless young 

 all firmly attached to teats within her pouch. When the young were 

 forcibly drawn away the much elongated teats were seen to have 

 extended well into their throats. Several other litters of similar 

 young were examined. The lips seem to be practically immobile ; 

 the mouth a very small, round opening into which the teat fits so 

 snugly that one wonders how it could have been introduced at the 

 time of the birth of so embryonic an animal. When the young are 

 detached the open mouth retains the shape of the teat ; they begin 

 at once to show their discomfort by making a slight hissing noise, 



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